Integrated Final Report to Congress and Legislative Environmental Impact Statement. Mississippi River Gulf Outlet Deep-Draft De-authorization Study

Transcription

1 Integrated Final Report to Congress and Legislative Environmental Impact Statement for the Mississippi River Gulf Outlet Deep-Draft De-authorization Study Volume 1 MAIN REPORT by U. S. Army Corps of Engineers New Orleans District November 2007 (Revised June 2008)

2 LEGISLATIVE ENVIRONMENTAL IMPACT STATEMENT Mississippi River-Gulf Outlet (MRGO) Deep-Draft De-authorization Study LEAD AGENCY: U.S. Army Corps of Engineers (USACE), Mississippi Valley, New Orleans District. ABSTRACT: The U.S. Congress has directed the Secretary of the Army, acting through the Chief of Engineers, to develop a plan for de-authorization of deep-draft navigation for the MRGO from the Gulf Intracoastal Waterway (GIWW) to the Gulf of Mexico. The plan shall be integrated into the Louisiana Coastal Protection and Restoration Plan. The MRGO is authorized as a 36-foot deep, 500-foot bottom width waterway (38-foot deep, 600-foot bottom width in the Bar Channel), connecting the city of New Orleans to the Gulf of Mexico. The Sound Reach of the MRGO experienced severe shoaling during Hurricane Katrina. A collaborative planning effort with numerous stakeholders identified common measures supported by many stakeholders. For planning purposes, the future without de-authorization was determined to be continuation of the authorized deep-draft channel at full width. In the December 2006 Interim Report, four alternatives were developed that would allow continued shallow-draft navigation, three that completely closed the MRGO from the GIWW to the Gulf of Mexico, and one that would cease all navigation maintenance activities on the MRGO from the GIWW to the Gulf of Mexico. An economic evaluation of channel navigation use does not demonstrate a Federal interest in continued operation and maintenance of the channel. An assessment of the benefits to costs of the channel shows a ratio of less than unity. All alternatives that included maintenance of shallow-draft navigation were screened from further consideration based on this economic analysis. Two alternatives that would completely close the channel were eliminated due to cost. Four alternatives were studied in detail: The Future Without De-authorization; Alternative 1 Construct a Total Closure Structure across the MRGO near Bayou La Loutre Immediately; Alternative 2 Phased Construction of a Total Closure Structure across the MRGO near Bayou La Loutre (Construction would begin with a weir and be completed with a total closure structure); and Alternative 3 Cease All MRGO Operations and Maintenance Dredging Activities. Alternative 2 was later dropped from further evaluation. Present channel conditions accommodate navigation up to a 22-foot draft. Vessels may attempt to navigate the channel after it is de-authorized; therefore, some form of positive closure of the channel should be constructed. The most suitable closure would be a total closure structure of rock. Locating this structure is based on two main considerations: preventing navigation and engineering criteria. Closure to navigation could occur at any point along the channel, but closure near the Bayou La Loutre ridge provides the most stable foundation because of proximity to the historic Bayou La Loutre ridge and it is the narrowest section of the channel (see Section 2.5.1, Preliminary Engineering on Alternatives Evaluated in Detail). Alternative 1 has been identified as the Recommended Plan. The Recommended Plan calls for de-authorization of navigation on the MRGO from mile 60 at the southern bank of the GIWW to the Gulf of Mexico. This plan could produce environmental benefits through partial restoration of estuarine salinity gradients and tidal conditions. It also could prevent the loss of a significant percent of the 2,343 net acres of marsh expected to be lost with the future without de-authorization. Salinity stratification would be reduced north of the total closure structure which is anticipated to reduce salinity stratification in Lake Pontchartrain. This could improve the aquatic ecosystem in the lake. All of these factors outweigh the disadvantage of Alternative 1, which is a slightly lower average annual net economic benefit than Alternative 3. The existing MRGO bank stabilization features and jetties would be de-authorized, but remain in place. Aids to navigation and channel markers would be removed at the discretion of the United States Coast Guard. The estimated total project construction cost of the total closure structure is $24,684,150. Total average annual costs for the Recommended Plan (including O&M and cost to navigation) are estimated at approximately $5.1 million and total average annual benefits are estimated at $12.5 million. This results in an estimated total average annual net benefit of $7.4 million. Comments or Questions: Please send comments or questions on this LEIS to the U.S. Army Corps of Engineers, New Orleans District, Attention: Sean P. Mickal., P.O. Box 60267, New Orleans, LA Phone: (504) The official closing date of document availability will be 30 days from the date on which the Notice of Availability for this Final LEIS appears in the Federal Register.

3 EXECUTIVE SUMMARY S.1. FINAL REPORT TO CONGRESS AND LEGISLATIVE ENVIRONMENTAL IMPACT STATEMENT This Final Report to Congress and Legislative Environmental Impact Statement (LEIS) present the findings of a congressionally requested study on the de-authorization of deepdraft navigation on the Mississippi River-Gulf Outlet (MRGO) between the Gulf Intracoastal Waterway (GIWW) and the Gulf of Mexico. This document provides comprehensive documentation of the MRGO Deep-Draft De-authorization Study. Traditionally, a Report to Congress and LEIS would be produced as two separately bound documents. However, a single integrated document meets the requirements of the National Environmental Policy Act (NEPA) and the USACE decision-making process without duplication. The main table of contents includes asterisks for traditional NEPA required chapters and sections to allow ready access for those specifically interested in the NEPA compliance review. The report organization and contents are intended to allow the reader to become familiar with the history of the MRGO Deep-Draft De-authorization Study. The information provided includes study purpose, background, and decision process. The document also describes the direct, indirect, and cumulative environmental effects attributable to alternative plans. Public involvement and agency coordination efforts are documented, as well as technical analyses. The document concludes with a detailed description of the Recommended Plan, which is to construct a total closure structure across the MRGO near Bayou La Loutre in one construction effort. A Legislative Environmental Impact Statement (LEIS) is the detailed statement required by Section 102(2)(C) of the National Environmental Policy Act (NEPA), 42 U.S.C. 4332(2)(C), to be included in a recommendation or report on a legislative proposal to the Congress. Preparation of a LEIS must conform to the requirements of the NEPA implementing regulations, codified at 40 CFR pts , except that (1) there need not be a scoping process; and (2) the LEIS shall be prepared in the same manner as a draft statement, but shall be considered the detailed statement required by statute, 40 CFR (b). S.2 STUDY AUTHORITY The U.S. Congress has directed the Secretary of the Army, acting through the Chief of Engineers, to develop a plan for de-authorization of deep-draft navigation for the Mississippi River-Gulf Outlet (MRGO) from the Gulf of Mexico to the Gulf Intracoastal Waterway (GIWW). The Emergency Supplemental Appropriations Act for Defense, the Global War on Terror, and Hurricane Recovery, 2006 (Public Law ), reads in part: the Secretary of the Army, acting through the Chief of Engineers, utilizing $3,300,000 of the funds provided herein shall develop a i

4 comprehensive plan, at full Federal expense, to de-authorize deep-draft navigation on the Mississippi River-Gulf Outlet, Louisiana, extending from the Gulf of Mexico to the Gulf Intracoastal Waterway: Provided further, That, not later than 6 months after the date of enactment of this Act, the Secretary shall submit an interim report to Congress comprising the plan: Provided further, That the Secretary shall refine the plan, if necessary, to be fully consistent, integrated, and included in the final report to be issued in December 2007 for the Louisiana Coastal Protection and Restoration Plan. House Report provides a Congressional conference committee manager s statement accompanying the legislative language further directing that: The plan shall include recommended modifications to the existing authorized current use of the Outlet, including what navigation functions, if any, should be maintained and any measures for hurricane and storm protection. The plan shall be developed in consultation with St. Bernard Parish, the State of Louisiana, and affected Federal Agencies. Congressional direction to prepare a deep-draft de-authorization plan for the MRGO also requires that the plan be fully consistent and integrated with the Louisiana Coastal Protection and Restoration (LACPR) plan. Development of the LACPR plan focuses on identifying a comprehensive plan for flood control, coastal restoration, and hurricane protection in south Louisiana. The future of the MRGO navigation channel is a key decision that affects directions on related projects in the area such as hurricane protection, ecosystem restoration, and navigation. Resolving questions about the future depth and use of the MRGO channel could provide a baseline for developing plans and designs for other related projects. The MRGO de-authorization plan is being integrated into ongoing work to develop and evaluate measures for the LACPR plan. Specific work to integrate the components of the MRGO plan with the LACPR plan includes storm surge modeling, environmental planning, and prioritization. Every effort has been made to accelerate completion of the MRGO Final Report and LEIS in accordance with the Congressional direction found in Title IV, Chapter 3, Section 4304 of the "U.S. Troop Readiness, Veterans' Care, Katrina Recovery, and Iraq Accountability Appropriations Act, 2007" (Public Law ). The MRGO Final Report and LEIS will be transmitted to the Congress as soon as is practicable. The MRGO Final Report and LEIS will also be included in the LACPR Final Report. At the time this report was being released for State and Agency review, the Water Resources Development Act of 2007 (WRDA 2007) became law expanding the scope of the study authority provided by Public Law to include ecosystem restoration. In addition, pursuant to WRDA 2007 Section 7013, upon submission of the final report to Congress, the MRGO from the Gulf of Mexico to Mile 60 at the southern bank of the GIWW is no longer authorized. Section 7013 also authorizes the Secretary of the Army to carry out a plan to close the MRGO and to restore and protect the ecosystem substantially in accordance with the final report subject to the Secretary s determination ii

5 that the plan is cost-effective, environmentally acceptable, and technically feasible. This report preliminarily addresses the ecosystem restoration requirements of WRDA 2007; however, a supplemental report to completely address the ecosystem restoration requirements of WRDA 2007 will be submitted at a later date. WRDA 2007 Section 7013 is provided below in its entirety: SEC MISSISSIPPI RIVER-GULF OUTLET. (a) DEAUTHORIZATION. (1) IN GENERAL. Effective beginning on the date of submission of the plan required under paragraph (3), the navigation channel portion of the Mississippi River-Gulf Outlet element of the project for navigation, Mississippi River, Baton Rouge to the Gulf of Mexico, authorized by the Act entitled An Act to authorize construction of the Mississippi River-Gulf outlet, approved March 29, 1956 (70 Stat. 65) and modified by section 844 of the Water Resources Development Act of 1986 (100 Stat. 4177) and section 326 of the Water Resources Development Act of 1996 (110 Stat. 3717), which extends from the Gulf of Mexico to Mile 60 at the southern bank of the Gulf Intracoastal Waterway, is not authorized. (2) SCOPE. Nothing in this paragraph modifies or deauthorizes the Inner Harbor navigation canal replacement project authorized by that Act of March 29, (3) CLOSURE AND RESTORATION PLAN. (A) IN GENERAL. Not later than 180 days after the date of enactment of this Act, the Secretary shall submit to the Committee on Environment and Public Works of the Senate and the Committee on Transportation and Infrastructure of the House of Representatives a final report on the deauthorization of the Mississippi River-Gulf outlet, as described under the heading INVESTIGATIONS under chapter 3 of title II of the Emergency Supplemental Appropriations Act for Defense, the Global War on Terror, and Hurricane Recovery, 2006 (120 Stat. 453). (B) INCLUSIONS. At a minimum, the report under subparagraph (A) shall include (i) a plan to physically modify the Mississippi River-Gulf Outlet and restore the areas affected by the navigation channel; (ii) a plan to restore natural features of the ecosystem that will reduce or prevent damage from storm surge; (iii) a plan to prevent the intrusion of saltwater into the waterway; (iv) efforts to integrate the recommendations of the report with the program authorized under section 7003 and the analysis and design authorized by title I of the Energy and Water Development Appropriations Act, 2006 (119 Stat. 2247); and (v) consideration of (I) use of native vegetation; and (II) diversions of fresh water to restore the Lake Borgne ecosystem. (4) CONSTRUCTION. The Secretary shall carry out a plan to close the iii

6 Mississippi River-Gulf Outlet and restore and protect the ecosystem substantially in accordance with the plan required under paragraph (3), if the Secretary determines that the project is cost-effective, environmentally acceptable, and technically feasible. S.3 OVERVIEW OF STUDY AREA The study area is located in southeastern Louisiana in St. Bernard, Orleans, Jefferson, St. Tammany, St. Charles, St. John the Baptist, and Tangipahoa Parishes. It covers the Middle and the Lower Pontchartrain Basin. The Middle Basin consists of Lake Pontchartrain with its adjacent cities and towns, and surrounding wetlands. The Lower Basin consists of Lake Borgne, the MRGO channel, Chandeleur and Breton Sounds, a small portion of the Gulf of Mexico, and the surrounding wetlands (Figure S.1). Figure S.1 Study Area S.4 BACKGROUND ON THE MRGO The MRGO provides a shorter navigation route from the Gulf of Mexico to the Port of New Orleans tidewater facilities compared to using the Mississippi River to access the port. Construction of the MRGO channel began in 1958 and was completed in iv

7 The channel extends from the Inner Harbor Navigation Canal (IHNC) in New Orleans to the 38-foot depth contour in the Gulf of Mexico (see Figure S.2). The stretch contiguous with the GIWW is the called the GIWW Reach (mile 66-60). Where the channel diverts from the GIWW and runs through wetlands for 37 miles is known as the Inland Reach (mile 60-23), which defines the southwest boundary of the Golden Triangle (see Sections 1.4, 4.5 and 4.6 of the Report). The 23 miles through Breton and Chandeleur Sounds is called the Sound Reach (mile 23-0). The portion in the Gulf of Mexico is the Bar Channel (mile 0 to -9.4). All reaches of the MRGO navigation channel are authorized as a 36-foot deep, 500-foot bottom width waterway with the exception of the Bar Channel which is authorized as a 38-foot deep, 600-foot bottom width waterway. MRGO channel construction was authorized by a March 29, 1956 Act of Congress (Public Law ) as a modification to the existing project for Mississippi River, Baton Rouge to the Gulf of Mexico. The Act authorized construction of the MRGO Project substantially in accordance with the recommendation of the Chief of Engineers contained in House Document No. 245, 82 nd Congress. In addition to recommending construction of the channel, the Chief of Engineers recommended the construction of (1) protective jetties at the entrance to the channel from the Gulf of Mexico; (2) a permanent retention dike through Chandeleur Sound and a wing dike along the islands as required; (3) a turning basin with a project depth of 36 feet Mean Low Gulf (MLG), a width of 1,000- feet and a length of 2,000 feet at the junction of the new channel and the Inner Harbor Navigation Canal; and (4) a highway bridge with approaches to carry Louisiana State Highway 61 over the channel. All of these features were constructed, with the exception of the permanent retention dike through Chandeleur Sound and the wing dike along the islands. Public Law also authorized replacement of the existing IHNC Lock when economically justified. In 1968, the River and Harbor Act (Public Law ) authorized the Michoud Canal Project as a modification of the MRGO Project. The Michoud Canal Project authorized a deep-draft navigation channel in the GIWW and Michoud Canal by enlargement to a depth of 36 feet over a bottom width of 250 feet from the MRGO channel to and including a turning basin 800 feet square at the north end of the Michoud Canal. The Michoud Canal Project was constructed; however, the IHNC Lock has not yet been replaced. The Federal government is responsible for constructing, operating, and maintaining all features of the MRGO Project, including the Michoud Canal Project, with the exception of the highway bridge and its approaches, which is owned, operated, and maintained by non-federal entities. The Port of New Orleans, the non-federal project sponsor, is responsible for furnishing free of cost to the Federal government all lands, easements, rights-of-way, relocations, and disposal areas (LERRDs) required for construction and maintenance of the MRGO Project. When the MRGO Project was built approximately 3,150 acres of marsh, 100 acres of wetland forest and 830 acres of shallow open water were converted to the deep water navigation channel between the GIWW and the Gulf of Mexico. The dredge material v

8 from channel construction was placed in a disposal area that was about 4,000 feet wide in most places and immediately southwest of the channel. The material in this disposal area was piled about 10 feet high and covered about 12,440 acres of marsh, 1,410 acres of wetland forest and 3,920 acres of shallow open water (USACE 1999). It is estimated that habitat shifts caused by saline waters brought in by the MRGO might have caused the following in areas adjacent to the MRGO: 3,350 acres of fresh/intermediate marsh and 8,000 acres of cypress swamp converted to brackish marsh and 19,170 acres of brackish marsh and swamp became saline marsh (USACE 1999). Bank erosion along the MRGO has been estimated to occur at rates of between 27 and 38 feet per year on the Inland Reach (USACE 2004). Between 1964 and 1996, 5,324 acres of marsh have been lost adjacent to the MRGO channel (mile 66 to 21). Operation and maintenance of the MRGO channel has required the construction of additional project features. Bank stabilization measures, also called foreshore protection, have been constructed along several reaches of both the north and south banks of the GIWW and Inland Reaches to prevent sloughing of the bank into the channel and to protect adjacent wetlands and levees. Bank stabilization measures exist in the following locations: 1) MRGO north bank (Miles 66-60, Miles , Miles 43 41, Miles , Miles , Miles ), and 2) MRGO south bank (Miles 66-60, Miles 60-47, Articulated Concrete Mattress (ACM) Miles and 37.3 to 36.5). In addition, Miles 23.2 to 20.8 of the north and south jetties provide foreshore protection for adjacent wetlands. Many disposal sites have been designated for maintenance of the MRGO Project. These include numerous upland disposal sites and beneficial use sites for wetlands restoration and nourishment. Dredged material was used beneficially from 1985 to An average of about 16 acres per year was created in the Inland Reach. Shallow open water areas on the north and south side of the jetties have been used for the placement of dredged material in a manner conducive to wetland creation. An average of about 17 acres per year was created behind the jetties. Dredged material has also been placed at an offshore feeder berm to nourish Breton Island and in shallow open water immediately adjacent to Breton Island to restore barrier island habitat destroyed by erosion and storms. About 21 acres per year were created on Breton Island. In the area behind the south jetty, dredged material has been placed in an effort to create marsh. Dredged material also has been placed at two-mile intervals across Breton Sound in an attempt to create islands. These areas have been used, but no islands have been created. There is also an approximately 5,000 acre EPA-designated Ocean Dredged Material Disposal Site (ODMDS) located parallel to and south of the channel from mile 4 to mile -10. Only the portion from mile -4 to mile -10 has been recently used for disposal. Direct costs of construction, operation, and maintenance of the MRGO have been funded by the Federal government. These direct costs have totaled over $580 million since The average annual operations and maintenance expenditures for the MRGO were $12.5 million (in 2000 dollars). However, following tropical storms and hurricanes, supplemental expenditures have often been required to return the MRGO to the vi

9 authorized dimensions. Since 1998, the $12.5 million has not allowed for dredging of the channel to its full-authorized dimensions. The GIWW Reach has not been dredged since From 1998 to 2005, the Inland Reach was maintained to a minimum 300-foot bottom width; the Sound Reach to a minimum 450-foot bottom width; and the Bar Channel to a minimum 500-foot bottom width. There has been no channel maintenance dredging in any reach of the MRGO since Hurricane Katrina in Sections of the MRGO experienced severe shoaling during Hurricane Katrina, leading to a current controlling channel depth of approximately 22 feet. The estimated cost to return the channel to authorized dimensions (36 feet deep by 500 foot bottom width; 38 feet deep by 600 foot bottom width in Bar Channel) is $130,444,870 based on October 2006 price levels. However, as discussed previously, for the past several years prior to Hurricane Katrina the channel has been maintained to reduced dimensions in some reaches. The estimated cost to return the channel to 36 feet deep by 300 foot bottom width in all reaches is $62,380,000 based on October 2006 price levels. For this deauthorization study, although no current plans exist to dredge the MRGO, it is important to estimate these costs for comparison purposes in evaluating future alternatives for modifying the channel. After Hurricane Katrina, the U.S. Congress passed two laws providing funds for emergency repairs or authorizing other actions related to the MRGO navigation channel. Chapter 3, under Division B of Title I of the Department of Defense, Emergency Supplemental Appropriations to Address Hurricanes in the Gulf of Mexico, and Pandemic Influenza Act, 2006 (Public Law ) provided $75,000,000 for authorized operation and maintenance (O&M) activities along the MRGO. Section 2304 of Chapter 3 in Title II of the Emergency Supplemental Appropriations Act for Defense, the Global War on Terror, and Hurricane Recovery, 2006 (Public Law ) clarified that these funds were to be used for "the repair, construction or provision of measures or structures necessary to protect, restore or increase wetlands, to prevent saltwater intrusion or storm surge." The USACE currently plans to use these funds for shoreline protection and marsh creation in the vicinity of the MRGO and Lake Borgne. In addition to providing funds to develop a comprehensive plan to de-authorize deepdraft navigation on the MRGO, Public Law authorized and provided $350 million for construction of enhanced hurricane protection for the IHNC, and $170 million to armor critical areas of the levee system. Efforts to plan and design these items are underway. vii

10 Figure S.2 Mississippi River-Gulf Outlet Area S.5 PURPOSE AND NEED The purpose of the study is to provide to Congress a comprehensive plan to de-authorize deep-draft navigation on the MRGO from the GIWW to the Gulf of Mexico. As requested in the authorizing legislation, an Interim Report to Congress was submitted in December The Interim Report to Congress stated that preliminary analysis indicated that the best plan was to close the MRGO from the GIWW to the Gulf of Mexico to both deep- and shallow-draft navigation. The MRGO comprehensive deauthorization plan is consistent with ongoing design and planning efforts related to storm protection and coastal restoration and long-term planning related to LACPR. In terms of design and planning, this MRGO de-authorization study and subsequent Congressional action defines the navigation future of the MRGO and thus enables other related projects to move forward with more certainty. The study also comports with the Chief of Engineer s 12 Actions for Change calling for effectively implementing comprehensive systems approaches to water resources problems. S.6 STUDY GOALS AND OBJECTIVES The goals and objectives for the MRGO deep-draft de-authorization study are derived entirely from the Congressional authorizing language and accompanying committee report. Those goals and objectives are: viii

11 Develop a comprehensive plan to de-authorize deep-draft navigation on the MRGO channel from the GIWW to the Gulf of Mexico Evaluate any navigation functions that should be maintained on the MRGO channel Identify measures for hurricane and storm damage reduction Refine the plan to be fully integrated and consistent with the LACPR Final Report to Congress S.7 PUBLIC INVOLVEMENT In response to Congressional direction to develop a MRGO de-authorization plan, the USACE established a plan of action for developing the Interim and Final Reports to Congress. Federal, state and local government parties, environmental groups, landowners, navigation interests, other organizations and individuals were invited to assist in preparation of the reports. A series of public stakeholder forums was held which included technical presentations and open discussions on topics including wetlands, navigation, storm protection, and the local economy. Each stakeholder was asked to identify their own plans for de-authorization of the MRGO from the GIWW to the Gulf of Mexico, environmental restoration measures in the vicinity of the MRGO, and hurricane protection components. Several stakeholder groups prepared such plans and presented them to the group. A public meeting was held on October 18, 2006 at the University of New Orleans and involved an open house where stakeholder groups were offered display space to present their plans. More than 150 people attended the public meeting, which included a formal presentation of the study process and scope from the USACE and an open comment period for public statements from citizens, organizations, and elected officials. Public comments made during this meeting were considered in formulating options for the Interim Report to Congress which was submitted in December A public information meeting was held on May 19, 2007 at Nunez Community College in Chalmette, Louisiana. The meeting offered attendees an opportunity to view a series of posters presented by the USACE on the study. In addition, various stakeholders displayed information and interacted with the meeting attendees. More than 100 attendees listened to a formal presentation regarding the alternatives evaluated in detail and the Recommended Plan. Following the presentation, attendees had the opportunity to ask questions. All attendees were made aware of the study schedule and process. Through the collaborative process some consensus measures emerged that were supported by many of the stakeholders. However, the different stakeholders could not agree on a plan to close or de-authorize the channel. Stakeholder recommendations varied from total closure to a sector gate allowing passage of vessels with a draft of up to 28 feet. Many of the measures from the stakeholder plans were incorporated into the Interim ix

12 Report to Congress. Collaborative planning continued after the submittal of the Interim Report to Congress and that approach remains a key component of the preparation of the Final Report to Congress and LEIS. The MRGO Deep-Draft De-Authorization Final Report to Congress will become part of the LACPR Final Report to Congress. (For further description of the proposed stakeholder plans, see Section 4.) S.8 PLAN FORMULATION In order to ensure that sound decisions are made, the USACE plan formulation process requires a systematic and repeatable approach. The Economic and Environmental Principles for Water and Related Land Resources Implementation Studies and The Economic and Environmental Guidelines for Water and Related Land Resources Implementation Studies (Planning Guidance Notebook or ER ) describe the USACE study process and requirements. Alternatives were formulated to minimize cost associated with the disposition of the de-authorized project. These alternatives were also evaluated against the following four criteria: Completeness - the extent to which a given alternative plan provides and accounts for all necessary investments or other actions to ensure the realization of the planned effects. Effectiveness - the extent to which an alternative plan alleviates the specified problems and achieves the specified opportunities. Efficiency - the extent to which an alternative plan is the most cost-effective means of alleviating specified problems and realizing the specified opportunities, consistent with protecting the Nation s environment. Acceptability - the workability and viability of the alternative plan with respect to acceptance by state and local entities and the public and compatibility with existing laws, regulations, and public policies. S.9 ALTERNATIVES FROM INTERIM REPORT TO CONGRESS A broad suite of options were identified for development of the deep-draft deauthorization plan in the December 2006 Interim Report to Congress. This initial array of alternatives included: Interim Report Alternative 1 Maintain a shallow-draft MRGO navigation channel with variations such as no structure, a salinity control weir at Bayou La Loutre, a salinity control gate at Bayou La Loutre (normally closed) and a storm protection gate at Bayou La Loutre (normally open). Interim Report Alternative 2 Close the MRGO channel to deep-draft and shallow-draft vessels by: blocking the channel with a total closure structure across the MRGO at Bayou La Loutre; restoring both banks of Bayou La Loutre across the MRGO at Hopedale, Louisiana; or filling in the entire MRGO channel from the GIWW to the Gulf of Mexico. x

13 Interim Report Alternative 3 Cease all MRGO operations and maintenance activities (dredging, beneficial use, jetty repairs, and navigation aids). S.10 ALTERNATIVES ELIMINATED FROM FURTHER STUDY All of the alternatives identified in the Interim Report to Congress that included maintenance of the MRGO channel for shallow-draft navigation were eliminated from further consideration based on economic analysis. The plan to maintain shallow-draft navigation (and all stated variations) was eliminated because the projected economic return was not positive. The cost to maintain the channel on an annual basis would be much higher than the projected commerce it could generate. Restoring both banks of Bayou La Loutre was eliminated from further consideration because, while it achieves similar environmental and navigation results as putting a total closure structure across one bank, it would cost approximately twice as much to construct. There are also additional negative impacts to recreational and commercial vessel users caused by restricted access to Bayou La Loutre from the north. Filling the entire MRGO channel was eliminated from further consideration due to its high cost and the length of time required for full implementation. It is estimated that it would require approximately million cubic yards of dredged material to fill the channel from mile 60 to mile 25 at a cost of about $2.8 billion based on October 2006 price levels, and could take from 15 to 44 years to completely fill the channel. Other alternatives were suggested after release of the Interim Report to Congress. These included multiple closure locations, limited channel filling, shoreline restoration and stabilization, and vegetative plantings. Alternatives dealing with ecosystem restoration were deemed to be beyond the authority of the MRGO de-authorization study; however, they will be considered under LACPR and other appropriate authorities. In addition to study authority, alternatives were eliminated from further consideration based upon costs, impacts to the environment, limited availability of construction materials, constructability issues, and effectiveness in meeting the study goals and objectives. Alternatives recommended after release of the Interim Report are discussed in greater detail in Section 4 and in Appendix P. S.11 ALTERNATIVES EVALUATED IN DETAIL In order to prepare the Final Report to Congress and the Legislative Environmental Impact Statement, in addition to the future without de-authorization three Alternatives were carried into the final array of alternatives for detailed evaluation. The alternatives evaluated in detail are listed below: Future Without De-authorization - The channel would be dredged to the Congressionally authorized dimensions of 500-foot bottom width in the Inland and Sound Reaches and a 600-foot bottom width in the Bar Channel. The channel would be maintained at these widths. Dredged material would be used beneficially behind the jetties and on Breton Island. Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately; xi

14 Alternative 2 Phased Construction of a Total Closure Structure Across the MRGO Near Bayou La Loutre (phased construction would begin with a weir and be completed with a total closure structure); Alternative 3 Cease All MRGO Operations and Maintenance Dredging Activities Immediately. The following features are common to Alternatives 1, 2, and 3: The MRGO channel would be de-authorized for navigation from mile 60 at the southern bank of the GIWW to the Gulf of Mexico. Aids to navigation and channel markers would be removed at the discretion of the United States Coast Guard. Existing bank stabilization features and jetties would be de-authorized, but left in place. S.12 ALTERNATIVE 2 ELIMINATED FROM FURTHER EVALUATION Alternative 2 was eliminated from further evaluation based on the comparison of alternatives based on the four criteria in principles and guidelines presented in Section 2.6 and the assessment of planning risk and uncertainty presented in Section Therefore, Alternative 2 was not carried forward for the evaluation and comparison of environmental consequences presented in Section 3. Alternative 2 was eliminated from further evaluation because it was deemed to be less complete, effective, and acceptable than Alternative 1 and less efficient than Alternative 3. Additionally, the benefits that may be derived from shallow-draft navigation usage before 2014 under Alternative 2 are speculative in nature because of the planning risk and uncertainty surrounding the potential rate of future MRGO channel shoaling. Given the risk and uncertainty and the performance of the alternative when evaluated against the four criteria in principles and guidelines, Alternative 2 was eliminated from further evaluation. S.13 EXISTING CONDITIONS Shoaling in the MRGO channel caused by Hurricane Katrina limited the controlling depth to approximately 22 feet which has restricted deep-draft access. Many deep-draft businesses in the study area were severely impacted. Two companies chose to relocate to Mobile, Alabama. Others are trying to recover; some may plan to relocate. Deep-draft vessels are entering the MRGO light-loaded, calling on tidewater port facilities in New Orleans, and exiting through the IHNC Lock into the Mississippi River for outbound voyages. Some maritime interests have reported modifying operations by moving products over to Mississippi River docks for loading. Other companies have adopted xii

15 other modifications to continue commerce. Post-Katrina 230 jobs were lost from the MRGO-IHNC area due to relocation and downsizing. Shallow-draft facilities have essentially recovered. Orleans Parish shows a 34.6% reduction from pre-katrina jobs and St. Bernard Parish shows a 54.1% reduction. Traffic records from the Waterborne Commerce Statistics Center (WCSC) show MRGO utilization steadily increasing until reaching a peak in terms of tonnage carried in 1978 and in terms vessel trips in Both tonnage and total vessels have decreased since that time. Recent analysis of deep-draft navigation indicates that maintaining the authorized dimensions of the MRGO between the GIWW and the Gulf of Mexico is not costeffective and thus not economically justified. Average annual operations and maintenance (O&M) costs to dredge a single shipping lane in the Inland Reach and authorized width in other reaches are $12.5 million. However, maintaining a single shipping lane, which is half of the authorized dimensions, only produces approximately $3.7 million per year in transportation efficiencies. Efforts to operate and maintain the fully authorized dimensions (i.e. a two-lane channel 500 feet wide by 36 feet deep) would be even more costly and would not produce greater navigation benefits. The economic information available also indicates that it is not cost effective to maintain shallow-draft navigation on the channel between the GIWW and the Gulf of Mexico in terms of National Economic Development (NED) criteria. The total average annual costs to maintain a 12 ft shallow-draft channel are approximately $6 million whereas the estimated average annual benefits are approximately $1.2 million. Historically, the MRGO has also served as an alternate navigation route for shallow draft vessels during times of extreme congestion at the IHNC Lock or when the lock was inoperable. Before Hurricane Katrina some barge tows would travel downstream on the Mississippi River to Baptiste Collette Bayou, exit Baptiste Collette Bayou into Breton Sound, and then enter the MRGO. Eastbound tows would then travel back inland from Breton Sound on the MRGO to the GIWW Reach before continuing east to locations in Mississippi, Alabama, and Florida (westbound traffic would traverse the opposite route). The alternative route around the IHNC Lock is about 180 miles longer than a direct lock through from the GIWW to the Mississippi River. Vessel operators would weigh factors such as anticipated time of delay, added fuel consumption, weather, and insurance ratings when making a decision to proceed through the alternative route or to wait to pass through the lock. The bypass takes approximately 24 hours to navigate. Alterations to the Mississippi River have increased salinity in the study area by reducing the flow of freshwater in the region (USACE 2004). Prior to construction of the MRGO, typical tidal flow within the Breton Sound area was reduced as it moved across the marshes and wetlands inward toward Lake Borgne (USACE 2004). The Bayou La Loutre ridge provided a basin boundary that limited the flow of saline water from the Breton Sound area into Lake Borgne (Rounsefell 1964). The MRGO now provides a more direct flow of higher salinity, stratified water inland toward areas of St. Bernard and Orleans Parishes (Wicker, et al. 1981). This stratified water sinks to the bottom of Lake Pontchartrain where it moves with the lake bottom currents and can cover at least 1/6 of the lake s bottom during the spring and summer. This heavy saline water inhibits both xiii

16 mixing and oxygenation, generally leading to hypoxic (low oxygen) or anoxic (no oxygen) conditions near the lake bottom (Schurtz and St. Pe 1984). Between 1956 and 1990, 68,660 acres of wetlands were lost in the study area. Factors such as subsidence, navigation channels, oil and gas exploration and production, development and storms have contributed to these losses. Approximately 67 percent of the swamp in the study area was lost while saline marsh gained 8 percent. Marsh type is dependent on salinity which is generally determined by rainfall and man-induced changes such as channel and canal dredging. The exact locations and acreages of fresh and intermediate marshes in the study area have fluctuated over time, probably depending on rainfall during the year. Intermediate marsh has been present in the Central Wetlands three of the five years it has been mapped. Brackish marsh has decreased significantly in acreage and fluctuated slightly in location. From saline marsh was only found south of the Bayou La Loutre ridge and in the outer Biloxi Marshes. In 1988 saline marsh had encroached up the MRGO to about Bayou Dupre and into the Biloxi Marshes near the MRGO. By 1997, it was found further north along the MRGO, past Bayou Dupre. The study area is home to many species of importance to the state and nation. Wintering waterfowl and furbearers have declined in the study area since about 1970, however are still present. After about 1970, 22 species of freshwater fish were apparently no longer found in the Biloxi Marshes/Lake Borgne area. However six important sport fish seemed to be present in approximately the same numbers as prior to about The MRGO channel, adjacent waters and marshes and Lake Pontchartrain are essential fish habitat (EFH). The hypoxic-anoxic (H-A) zone in Lake Pontchartrain causes a reduction in the benthic community during H-A events. With regard to threatened and endangered (T&E) species, brown pelicans are found in the study area. Beneficial use of dredged material has nourished Breton Island and wintering piping plovers have utilized the island. Sea turtles in agreed-upon numbers have been taken in the Bar Channel. Detailed contract specifications to protect the Gulf sturgeon, manatee and various kinds of sea turtles have been used. Maintenance of the MRGO channel did not adversely affect T&E species. S.14 FUTURE WITHOUT DE-AUTHORIZATION The existing MRGO Project completed construction in 1968 at the authorized depth and width. Since construction, the project has been maintained at various depths and widths. For the past few years, the Inland Reach, the Sound Reach and Bar Channel have not been dredged to full dimensions. Rather, the channel has been maintained for one-way traffic only. Due to shoaling the current controlling depth is approximately 22 feet. However, to determine whether it is economically feasible to maintain the project and evaluate the environmental impacts for various levels of maintenance including closure, the future without de-authorization is assumed to be a project maintained at the authorized dimensions. The Future Without condition is equivalent to the no-action alternative. All alternatives will be compared to this future condition. When the Inland Reach is dredged to its full, authorized dimensions, all material from the Inland Reach would be placed in upland disposal areas because of difficulties in finding xiv

17 marsh creation sites unencumbered with oyster leases. Based upon previous practices, under the future without project scenario, material from the initial dredging of channel miles 27 to 23 would create approximately 157 acres of wetlands adjacent to and behind the north jetty. Material from the initial dredging of channel miles 23 to 14 would be placed behind the south jetty, creating approximately 1,297 acres of marsh. From channel miles 14 to 3.4, material would be placed at unprotected sites in the sound and it is unlikely that any marsh created would last more than a year because of exposure to open bay waves. Material from the initial dredging of channel miles 3.4 to -4 would be placed on Breton Island to create approximately 215 acres of marsh and barrier island habitat (see Appendix G). Following the restoration of the channel to its full dimensions, it would be maintained at a 500-foot bottom width for the 50-year period of analysis. A 600-foot bottom width would be maintained within the Bar Channel. However, future maintenance operations would depend on funding availability. Material from the Inland Reach would again be placed in upland confined disposal areas. From 1985 to 2004, while maintaining miles 27 to 3.4 to a 500-foot width, an average of approximately 17 acres was created each year behind the jetties. From 1993 to 2005, material between miles 3.4 to -4 was placed either at the feeder berm or just off Breton Island, creating an average of approximately 21 acres per year. It is assumed that these acreages would continue to be created for 50 years in the future without de-authorization (see Appendix G). Approximately 2,702 acres of marsh would be created in 50 years. At the same time 5,045 acres of marsh could be lost due to erosion. Thus, the estimated net loss is 2,343 acres over 50 years (see Appendix G). S.15 EVALUATION AND COMPARISON OF REMAINING ALTERNATIVES The Future Without De-authorization, Alternative 1 and Alternative 3 were analyzed in Section 3 using comparable information to assess relative consequences to the environment. The impact of each alternative across a range of significant resources is presented in Table The following text compares the Future Without De- Authorization, Alternative 1, and Alternative 3 relative to this assessment of environmental impacts. A comparison of total project construction costs and average annual benefits and costs for each alternative are presented in Table 2.4. Under the Future Without De-authorization, it is anticipated that navigation use would return to pre-katrina levels; however, it has been determined that this level of navigation use does not economically justify a continued Federal interest in the authorized Project. The Future Without De-authorization also results in net environmental losses. Approximately 2,702 acres of marsh could be created by beneficial use in 50 years, but, about 5,045 acres of marsh could be lost to wake and wave erosion. Thus there could be an estimated net loss of about 2,343 acres of marsh during the 50 year period of analysis. There would be no salinity reduction in the Pontchartrain Basin under the Future Without De-authorization and habitat types would remain as they are today. The "H-A Zone" in Lake Pontchartrain would continue to occur nearly every year. The Future Without De- xv

18 authorization has little compatibility with other potential ecosystem restoration efforts, such as a freshwater diversion structure at Violet. Alternative 1 provides a physical closure to eliminate attempted navigation on the channel after de-authorization and maximizes protection of the environment. In addition, compatible with the study authority (Section 1.2), Alternative 1 has the highest compatibility with other potential ecosystem restoration efforts being considered under LACPR, such as a freshwater diversion structure at Violet. Alternative 1 immediately closes the MRGO to all navigation, thereby eliminating potential through navigation which could occur prior to the channel shoaling in naturally. It yields the fewest average annual net economic benefits ($7.8 million) because all navigation benefits are lost as soon as the total closure structure is installed. Shallow-draft tows that use the MRGO as an alternate route when the IHNC is congested or unexpectedly closed could no longer do so. (Note: this cost is included in calculation of net economic benefits). There is the potential for erosion to increase along the banks of Bayou La Loutre and other waterways if vessels currently using the MRGO channel utilize the other waterways as alternative routes; however, although this is not quantifiable the positive impacts of the alternative far outweigh any impacts to alternative routes. Alternative 1 could prevent a significant percentage of the 2,343 net acres of marsh estimated to be lost over 50 years under the future without condition. Greater salinity reduction and vegetation change to historic habitat types is anticipated to occur over a larger area. It is estimated that there could be a reduction in the size of the H-A zone in Lake Pontchartrain. If authorized and funded, Alternative 1 could be built in one construction effort lasting an estimated 170 days. Alternative 2 was eliminated from further evaluation. Alternative 3 is the least costly alternative and does not address negative environmental impacts associated with erosion and increased salinity associated with future without deauthorization. It does not provide a physical closure of the channel and therefore through navigation of the channel would be limited only by natural shoaling. Additionally, Alternative 3 is not as compatible with the ecosystem restoration goals of LACPR as Alternative 1. Alternative 3 yields the greatest average annual net economic benefits ($9.1 million) because it requires minimal investment and because shallow-draft navigation benefits would only be limited by natural shoaling within the channel. Alternative 3 has no construction costs, except 1) aids to navigation and channel markers would be removed at the discretion of the United States Coast Guard and 2) the USACE would dispose of some existing disposal and channel easements. This alternative could be implemented almost immediately after Congressional authorization and appropriation. Shallow-draft navigation would be prohibited over time because the channel would not be maintained; however shallow-draft navigation would not be impeded by a structure. Most shallow-draft navigation would be unable to use the Sound Reach of the channel after about Shallow-draft tows that use the MRGO as an alternative route when the IHNC is congested or unexpectedly closed could no longer do so after about 2014 (Note: this cost is included in the calculation of net economic benefits). It is estimated that slightly more marsh would be lost than under Alternative 1, but significantly less than under the future without condition. It is estimated that Alternative 3 is unlikely to xvi

19 influence salinity or marsh vegetation types or reduce the H-A zone in Lake Pontchartrain. Additionally, potential future ecosystem restoration measures, such as a freshwater diversion structure at Violet, could be more difficult to implement than under Alternative 1. For example, without a structure in the MRGO channel, a much larger freshwater diversion would be required at Violet, which would increase cost significantly and decrease the ability to control desired environmental results within the greater Pontchartrain Basin. Assessment of this alternative also raised questions about whether or not the alternative could be classified as comprehensive and therefore responsive to the Congressional direction. S.16 RATIONALE FOR SELECTING RECOMMENDED PLAN Alternative 1 has been selected as the Recommended Plan. The Recommended Plan is consistent with the study authority as described in Public Law and explained in House Report (see Section 1.2). The Recommended Plan also fulfills the study purpose and need (see Section 1.5) and the study goals and objectives (see Section 1.6) which are derived from the study authority. The Recommended Plan presents a comprehensive plan to de-authorize all navigation on the MRGO channel from the GIWW to the Gulf of Mexico; proposes that navigation function be maintained outside of the GIWW to Gulf of Mexico portion of the channel; proposes plan features; and proposes existing project features to be de-authorized or to remain authorized (see Section 6.1). The Recommended Plan minimized the costs associated with the disposition of the de-authorized project while best meeting the criteria of completeness, effectiveness, efficiency and acceptability.. The Recommended Plan results in $7.8 million in net annual benefits, reduces negative environmental impacts in the study area through reductions in erosion and salinity, and may reduce the size of the H-A zone in Lake Pontchartrain. The Recommended Plan was developed in consultation with St. Bernard Parish, the State of Louisiana, and affected Federal Agencies, as well as other stakeholders and the general public (see Section 4). While the Recommended Plan does not propose hurricane or storm damage reduction features, the Recommended Plan was identified because it is more compatible with the goals of LACPR than Alternative 3. The Recommended Plan is acceptable, complete and effective as evaluated under the P&G criteria. Although the plan is not the least cost alternative, it is recommended because it fully meets three of the four P&G criteria while the cost alternative only fulfills the efficiency criteria. Additionally, the Recommended Plan is consistent with all of the alternatives being evaluated under LACPR and can be fully integrated into any of the LACPR plans under consideration. The Recommended Plan provides for reduced salinities in areas targeted for restoration under LACPR, LCA, CWPPRA, as well as, restoration efforts of other Federal and State agencies. Reduction in salinities will improve the effectiveness of, and likely reduce the cost of, ecosystem restoration measures planned for these areas. The MRGO Final Report and LEIS will be included in the LACPR Final Report. Specific features of the Recommended Plan are addressed in Section 6. S.17 DESCRIPTION OF THE RECOMMENDED PLAN The project delivery team has developed detailed design and cost information for the recommended plan. Cost information presented for the Recommended Plan is based on xvii

20 advanced design and therefore differs from the costs presented for Alternative 1 which were based on preliminary design information. Advanced design information has been generated through the analysis of field engineering data recently collected at the proposed closure structure location. Field data includes bathymetric surveys and subsurface geotechnical borings. Engineering analysis of the information was used to developed design and cost information to a feasibility level of detail. This level of information was developed only for the recommended plan not the entire array of alternatives. This section of the report provides the feasibility level design and cost information. The team has not updated information in earlier parts of the report because the added information does not change plan selection. This assessment is based upon the initial screening of navigation alternatives and subsequent assessment that remaining alternatives involving rock would change proportionally with the recommended plan. Under the Recommended Plan, that portion of the MRGO channel from mile 60 at the southern bank of the GIWW to the Gulf of Mexico would be de-authorized for all navigation use. The MRGO channel (mile 66 60), the Michoud Canal Project, and the IHNC Lock Replacement Project would remain authorized. As part of the Plan, a total closure structure would be built of rock downstream of the south ridge of Bayou La Loutre in St. Bernard Parish, Louisiana (see Figure S.3). The structure would connect the two sides of the ridge, a distance of approximately 950 feet. The top width of the structure would be 12 feet and the elevation would be + 7 feet NAVD 88. Following completion of construction, the elevation of the structure will not be less than +4 feet NAVD 88. The side slopes of the structure would be 1 V to 2 H and the bottom width would be 450 feet. Quarry run A stone would be used to increase fines in the mix and minimize voids and water exchange. The structure would cover nearly 10 acres of water bottoms. Overbank extensions would be necessary on either side of the structure to constrict flow during high water events and prevent flanking of the channel closure. These overbank tie-ins would be approximately 50 feet wide and 7 feet high and extend inshore approximately 150 feet on the south bank and approximately 250 feet on the north bank. Construction of these overbank extensions will impact 0.5 acres of marsh on the north bank and 0.3 acres of scrub shrub on the south bank. Approximately 391,500 tons of stone would be used. A barge-mounted dragline would be used to place the rock. Every effort would be made to construct the total closure structure during the May through September window when Gulf sturgeon are in the rivers and not the estuaries. The Federal government would construct the total closure structure. Navigation aids and channel markers would be considered for removal at the discretion of the United States Coast Guard. Existing bank stabilization features and jetties would be de-authorized but remain in place. Maintenance of the existing bank stabilization features and possible reapplication or realignment of the jetties could be investigated under LACPR or other appropriate authorities. Disposal easements and perpetual channel easements not required for continued operation and maintenance of authorized segments of the MRGO Project would be released. Other property not required for continued operation and maintenance of authorized segments of the MRGO Project would be disposed of in accordance with the Federal Property and Administrative Services Act of 1949, as amended, 40 U.S.C. 471 et seq. A non-federal sponsor would be required to acquire xviii

21 any real estate necessary to implement the Recommended Plan and for operation, maintenance, repair, rehabilitation, and replacement (OMRR&R) of the total closure structure. In addition, the non-federal Sponsor would be required to hold and save the Government free from all damages arising from the construction, operation, maintenance, repair and replacement of the total closure structure, except for damages due to the fault or negligence of the Government or its contractors. The construction costs of the total closure structure would be 100% Federal (except real estate) and the OMRR&R costs of the total closure structure would be 100% non-federal. The estimated total project construction cost of the rock total closure structure is $24,684,150 based on October 2006 price levels. Total average annual costs for the Recommended Plan (including OMRR&R costs and the costs to navigation) are estimated to be approximately $5.1 million and total average annual benefits are estimated to be $12.5 million (savings derived from not dredging the authorized channel). This results in an estimated total average annual net benefit of $7.4 million. Estimated construction costs, annual costs and benefits, and Federal/non-Federal cost breakdown are presented in Tables S.1 through S.4. Costs presented in these tables are based on advanced design of the Recommended Plan. Additionally, the Recommended Plan contemplates that measures undertaken pursuant to the authorization provided under the heading "Operation and Maintenance" in Title I, Chapter 3 of Division B of Public Law , as modified by Section 2304 in Title II, Chapter 3 of Public Law will be implemented conditioned on the non-federal sponsor for those measures assuming responsibility of OMRR&R of those measures at 100% non-federal cost. xix

22 Table S.1 Project First Costs Project First Costs MRGO Deep-Draft De-authorization Study Closure Structure (October 2006 Price Levels; Based on Advanced Design of Recommended Plan) Construction Items Cost ($) Mobilization and Demobilization 85,000 Stone Placement - Channel Proper 11,773,000 Stone Placement - Overbank Tie-Ins 403,650 Crushed Stone Blanket 3,400,000 Geotextile Separator Fabric 31,500 Clearing and Grubbing (Overbank) 11,000 Engineering and Design 863,700 Construction Management 1,256,300 Real Estate* 1,401,000 Removal of Aids to Navigation 700,000 Contingencies 4,759,000 Total Project Construction Costs 24,684,150 *Of the total Real Estate costs, $21,000 are associated with acquisition of real estate rights necessary for the construction of the closure structure. For an explanation of additional costs, see Appendix E. Table S.2 Equivalent Annual Benefits and Costs Equivalent Annual Benefits And Costs MRGO Deep-Draft De-Authorization Study Closure Structure (October 2006 Price Level, 50-Year Period of Analysis, Percent Discount Rate, Based on Advanced Design of Recommended Plan) Investment Costs: Total Project Construction Costs $24,684,150 Interest During Construction 452,000 Total Investment Cost $25,136,150 Average Annual Costs: Interest and Amortization of Initial Investment $ 1,264,000 Deep-Draft Transportation Cost 2,500,000 Shallow-Draft Transportation Cost 1,200,000 OMRR&R 172,000 Total Average Annual Costs $5,136,000 Average Annual Benefits $12,500,000 Net Annual Benefits $ 7,364,000 Benefit-Cost Ratio 2.4 to 1 Benefit-Cost Ratio (computed at 7%)* 2.3 to 1 *Per Executive Order xx

23 Table S.3 Economic Costs and Benefits of Recommended Plan MRGO Deep-Draft De-Authorization Study Economic Costs And Benefits of Recommended Plan (October 2006 Price Level, 50-Year Period of Analysis, Percent Discount Rate, Based on Advanced Design of Recommended Plan) Item Navigation Total Costs Allocated Benefits Allocated Benefits Costs Costs Investment Costs: Total Project Construction Costs $24,684,150 $24,684,150 Interest During Construction 452, ,000 Total Investment Cost $ 25,136,150 $ 25,136,150 Average Annual Costs: Interest and Amortization of Initial Investment $1,264,000 $1,264,000 Deep-Draft Transportation Cost 2,500,000 2,500,000 Shallow-Draft Transportation Cost 1,200,000 1,200,000 OMRR&R 172, ,000 Total Average Annual Costs $ 5,136,000 $ 5,136,000 Average Annual Benefits $ 12,500,000 $ 12,500,000 Net Annual Benefits $ 7,364,000 $ 7,364,000 Benefit-Cost Ratio 2.4 to to 1 Benefit-Cost Ratio (computed at 7%)* 2.3 to to 1 *Per Executive Order S.18 ISSUES TO BE RESOLVED Implementing the Recommended Plan would result in the abandonment of channel features constructed for purposes of shoreline protection, levee protection, and channel protection. These features include jetties in the offshore segments of the channel in Breton and Chandeleur Sounds, and foreshore protection segments along the portion of the Chalmette Loop Levee fronting the MRGO, and foreshore protection in various locations on the north bank of the channel fronting wetlands areas. Due to geologic conditions and the elimination of maintenance authority, these features are predicted to subside below the water line resulting in diminished functional performance against wave energies. xxi

24 Table S.4 Federal and Non-Federal Cost Breakdown MRGO Deep-Draft De-Authorization Study Federal and Non-Federal Cost Breakdown (October 2006 Price Level, 50-Year Period of Analysis, Based on Advanced Design of Recommended Plan) Responsibility Federal Non- Federal Total Project First Costs (Construction) Mobilization and Demobilization 100% Federal $85,000 $85,000 Stone Placement - Channel Proper 100% Federal $11,773,000 $11,773,000 Stone Placement - Overbank Tie-Ins 100% Federal $403,650 $403,650 Crushed Stone Blanket 100% Federal $3,400,000 - $3,400,000 Geotextile Separator Fabric 100% Federal $31,500 - $31,500 Clearing and Grubbing (Overbank) 100% Federal $11,000 $11,000 Engineering and Design 100% Federal $863,700 $863,700 Construction Management 100% Federal $1,256,300 $1,256,300 Real Estate* 100% Non-Federal $125,000 $1,276,000 $1,401,000 Removal of Aids to Navigation 100% Federal $700,000 $700,000 Contingencies 100% Federal $4,759,000 $4,759,000 Total Project First Costs $23,408,150 $1,276,000 $24,684,150 OMRR&R 100% Non-Federal $7,860,000 $7,860,000 Total Cost Share $23,408,150 $9,136,000 $32,544,150 *Of the total Real Estate costs, $21,000 are associated with acquisition of real estate rights necessary for the construction of the closure structure. For an explanation of additional costs, see Appendix E. S.19 AREAS OF CONCERN AND CONTROVERSY Construction of the MRGO Project resulted in the conversion of marsh, wetland forest and shallow open water habitat (USACE 1999). Erosion causes additional acres to be lost each year along the MRGO channel (USACE 2004). Citizens are concerned about coastal erosion, populations of wildlife and fisheries, and increased salinity in area water bodies. Many members of the public also feel that the loss of wetlands exacerbated the flooding of St. Bernard Parish during Hurricane Katrina. Many citizens of Orleans and St. Bernard Parishes firmly believe that the Inland Reach of the MRGO serves as a storm surge pathway during hurricanes. A number of reports concluded that the Inland Reach of the MRGO contributes very little to flooding when the surrounding marshes are inundated. Reports also indicate that to prevent storm sure in Lake Borgne from reaching the IHNC or GIWW Reach of the MRGO, flow through the GIWW Reach of the channel must be dramatically reduced or eliminated. The USACE is actively planning, designing and building numerous upgrades and new system components to increase the level of hurricane protection for the entire area. The connectivity between Lake Borgne and the GIWW Reach of the MRGO and IHNC is being addressed through efforts to provide comprehensive hurricane and storm protection through the Lake Pontchartrain and Vicinity Hurricane Protection project 100-year xxii

25 protection effort. See Section 1.8 and Appendix D for further discussions on the MRGO and storm surge. Figure S.3 Bayou La Loutre Ridge, site of the Total Closure Structure Stakeholders in the navigation industry have expressed concerns that when the MRGO is de-authorized from the GIWW to the Gulf of Mexico, shallow-draft vessels would no longer be able to use the channel as an alternate route when the Inner Harbor Navigation Canal Lock is congested or inoperable. Industry members believe this could present a serious problem for fuel transport and movement of other vital commodities. In evaluating this concern the USACE determined that although this potential event would be very rare, it nonetheless warrants attention and efforts to avoid such a scenario. However, based upon the economics evaluation of this study, expenditures to construct and maintain a shallow-draft feature for MRGO traffic are not justified. As such, the USACE, navigation industry representatives, and leaders from St. Bernard Parish are willing to work together to identify suitable alternative routes to alleviate this potential issue. Stakeholders in the shallow draft navigation industry have expressed concern that prolonged closure of the Inner Navigation Canal Association (IHNC) Lock with no alternate route available will cause significant income and employment impacts to businesses that rely on shipments traversing the IHNC Lock and that these impacts were xxiii

26 ignored in economic evaluations. However, as specified in USACE guidelines, effects on income levels and employment levels generally fall into the Regional Economic Development (RED) account. These effects are considered to be RED in nature because, 1) increases or decreases in income/employment levels in one region will tend to be offset by increases or decreases in income/employment levels in another region resulting in a minimal net effect to the nation, and, 2) losses in one region that are not captured by another region can often be made up at a later date in the initially impacted region. This is not to say that the income/employment impacts can not be National Economic Development (NED) in nature, or that the impacts are insignificant at a regional level, but that from a national perspective the net impacts are likely to be small. Given that this is the case and that NED impacts take priority over RED impacts, the economic evaluation performed for the MRGO De-Authorization Study chose not to quantify the income/employment implications of the various plans. Some groups are concerned that the replacement of the IHNC Lock is somehow directly connected to the de-authorization of MRGO to deep-draft navigation. Although these projects are related, the Recommended Plan is in no way dependent on the replacement of the lock or vice versa. Some vessels may choose to utilize Bayou La Loutre, a federally-authorized channel, to access Chandeleur Sound and numerous waterways in the Biloxi Marshes following installation of a total closure structure on the MRGO channel. Bayou La Loutre has a controlling depth of six feet limiting vessels to recreational and commercial fishing boats, small tugs and barges, and oil field service boats. Although the potential number of vessels that would use Bayou La Loutre and the potential impacts of diverted vessel traffic along the waterway cannot be quantified at this time, the overall environmental benefits of the Recommended Plan will far outweigh any potential impacts to Bayou La Loutre. Vessel traffic and shoreline erosion rates are monitored along Bayou La Loutre and other Louisiana waterways under private, state, and Federal efforts to implement coastal restoration plans. This investigation was conducted using a collaborative approach that included multiple stakeholder groups and the general public. A number of plan options, issues, and concerns were raised during study meetings with stakeholders. In addition, during preparation of the final study report the Corps of Engineers opened a 45-day public comment period as part of its compliance with the National Environmental Policy Act. All of the comments received during that period have been addressed. However, an issue of regional significance, the interconnection of the MRGO with other vital waterways in southeast Louisiana, remained unresolved in the Tentatively Selected Plan. The waterways of southeast Louisiana form a maritime transportation network facilitating the efficient shipment of goods and materials and linking interdependent industries. The Inner Harbor Navigation Canal is a key transition point within this system allowing eastwest traffic on the GIWW to cross the Mississippi River and allowing maritime access to points north along the Industrial Canal and into Lake Pontchartrain and points east and southeast on the MRGO. The IHNC Lock was constructed in the 1920's and has been xxiv

27 authorized for replacement to better accommodate modern maritime traffic. Options to implement the lock replacement are currently being developed in a Supplemental Environmental Impact Statement. Occasionally the lock experiences multi-day delays associated with high use and more rarely the lock is closed to vessel traffic for prolonged maintenance. In the event of delay or closure, the MRGO currently serves as an important link in an alternative route enabling traffic to by-pass the IHNC Lock and continue to points along the GIWW in Louisiana and neighboring states across the Gulf coast. The route is especially important for the movement of fuel, energy, and chemical products. In the days following Hurricane Katrina, the MRGO alternative route played an important role in enabling GIWW traffic to by-pass the closed IHNC Lock and the MRGO provided emergency access to severely damaged areas in and around New Orleans on the east bank of the Mississippi River. However, the economic evaluation of deep draft and shallow draft commerce found no National Economic justification for continued Federal investment in an MRGO navigation channel. Working with stakeholders the study team identified four alternative by-pass routes around the IHNC Lock that would not involve a fully open MRGO channel. In addition, the team identified an emergency plan that would allow temporary removal of the MRGO rock closure to allow vessel passage. However, none of the identified routes or options has been endorsed by navigation industry users. Varying reasons have been identified such as added travel time and expense and concerns about navigation safety raised by the U.S. Coast Guard. The routes deemed unsafe for navigation and those requiring new authority for construction dredging are not being pursued. Still, a long distance by-pass using the Mississippi-Ohio-Tennessee-Tombigbee route remains viable although obviously much less efficient. We recognize these concerns and have identified another option to reduce some of the risks associated with the recommended MRGO channel closure plan. This approach could entail sequencing a series of IHNC Lock maintenance works to be completed prior to implementing the MRGO closure project. Addressing these maintenance needs could improve the reliability of the IHNC Lock reducing the risks to the efficient operation of the waterborne transportation network. xxv

28 TABLE OF CONTENTS *Indicates traditional NEPA required sections. ABSTRACT*... ii EXECUTIVE SUMMARY*... i S.1. FINAL REPORT TO CONGRESS AND LEGISLATIVE ENVIRONMENTAL IMPACT STATEMENT... i S.2 STUDY AUTHORITY... i S.3 OVERVIEW OF STUDY AREA... iv S.4 BACKGROUND ON THE MRGO... iv S.5 PURPOSE AND NEED...viii S.6 STUDY GOALS AND OBJECTIVES...viii S.7 PUBLIC INVOLVEMENT... ix S.8 PLAN FORMULATION... x S.9 ALTERNATIVES FROM INTERIM REPORT TO CONGRESS... x S.10 ALTERNATIVES ELIMINATED FROM FURTHER STUDY... xi S.11 ALTERNATIVES EVALUATED IN DETAIL... xi S.12 ALTERNATIVE 2 ELIMINATED FROM FURTHER EVALUATION... xii S.13 EXISTING CONDITIONS... xii S.14 FUTURE WITHOUT DE-AUTHORIZATION... xiv S.15 EVALUATION AND COMPARISON OF REMAINING ALTERNATIVES.. xv S.16 RATIONALE FOR SELECTING RECOMMENDED PLAN... xvii S.17 DESCRIPTION OF THE RECOMMENDED PLAN... xvii S.18 ISSUES TO BE RESOLVED... xxi S.19 AREAS OF CONCERN AND CONTROVERSY... xxii SECTION 1 INTRODUCTION FINAL REPORT TO CONGRESS AND LEGISLATIVE ENVIRONMENTAL IMPACT STATEMENT* STUDY AUTHORITY* PROJECT AREA DESCRIPTION* BACKGROUND ON THE MRGO* STUDY PURPOSE AND NEED* STUDY GOALS AND OBJECTIVES PRIOR STUDIES, REPORTS AND PROJECTS Mississippi River and Tributaries (MR&T) Gulf Intracoastal Waterway (GIWW) Bayous La Loutre, St. Malo and Yscloskey, MRGO, Michoud Canal, Louisiana Project, Inner Harbor Navigation Canal Lock Replacement Project, Lake Pontchartrain and Vicinity, Louisiana, Hurricane Protection Project, Mississippi River Outlets, Venice, Louisiana, MRGO St. Bernard Parish, Louisiana, Reconnaissance Report, February Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA), xxvi

29 MRGO North Bank Foreshore Protection Evaluation, Coast 2050: Toward a Sustainable Coastal Louisiana, MRGO Reevaluation Study Environmental Assessment for the Lake Borgne Shoreline Protection Project Ecological Review, Lake Borgne and MRGO Shoreline Protection Continuing Authorities Program Louisiana Coastal Area Ecosystem Restoration Study (LCA 2004) Second Emergency Supplemental Appropriations Act to Meet the Immediate Needs Arising from the Consequences of Hurricane Katrina, 2005 (Public Law ) Department of Defense, Emergency Supplemental Appropriations to Address Hurricanes in the Gulf of Mexico, and Pandemic Influenza Act, 2006 (Public Law ) and Emergency Supplemental Appropriations Act for Defense, the Global War on Terror, and Hurricane Recovery, 2006 (Public Law ) Coastal Impact Assistance Program, Louisiana Coastal Protection and Restoration (LACPR), Integrated Ecosystem Restoration and Hurricane Protection: Louisiana s Comprehensive Master Plan for a Sustainable Coast, Environmental Assessments and Environmental Impact Statements THE MRGO SECTION 2 FORMULATION OF ALTERNATIVE PLANS* COLLABORATIVE PLANNING DEVELOPMENT OF ALTERNATIVES FOR INTERIM REPORT TO CONGRESS EVALUATION OF NAVIGATION FUNCTIONS THAT SHOULD BE MAINTAINED ALTERNATIVES ELIMINATED FROM FURTHER STUDY ALTERNATIVES EVALUATED IN DETAIL Preliminary Engineering on Alternatives Evaluated in Detail Assessment of Planning Risk and Uncertainty Description of Alternatives Evaluated in Detail COMPARISON OF ALTERNATIVES BASED ON FOUR CRITERIA IN PRINCIPLES AND GUIDELINES Completeness Effectiveness Efficiency Acceptability ALTERNATIVE 2 ELIMINATED FROM FURTHER EVALUATION EVALUATION AND COMPARISON OF REMAINING ALTERNATIVES RATIONALE FOR SELECTING RECOMMENDED PLAN SECTION 3 AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES* PROJECT AREA DESCRIPTION Land Characteristics Climate xxvii

30 3.2 SIGNIFICANT RESOURCES Water Quality Vegetation Wildlife Fisheries Essential Fish Habitat (EFH) Threatened and Endangered Species Natural and Scenic Rivers System Air Quality Recreation Resources Cultural Resources Aesthetics (Visual Resources) Navigation Business Employment Community Cohesion COMPARISON OF IMPACTS CUMULATIVE EFFECTS ANALYSIS Cumulative Effects Background Summary of Cumulative Effects SECTION 4 PUBLIC AND AGENCY INVOLVEMENT* INTRODUCTION STAKEHOLDER PARTICIPANTS STAKEHOLDER MEETINGS STAKEHOLDER PLANS St. Bernard Parish Plan LAKE PONTCHARTRAIN BASIN FOUNDATION PLAN Bring New Orleans Back Commission Plan Biloxi Marshlands Corporation Plan Stakeholder Consensus Items FINAL INTEGRATED ECOSYSTEM RESTORATION AND HURRICANE PROTECTION: LOUISIANA S COMPREHENSIVE MASTER PLAN FOR A SUSTAINABLE COAST, MISTER GO MUST GO PLAN LETTER FROM NATIONAL AND LOCAL ENVIRONMENTAL GROUPS, DATED JANUARY 26, MRGO WEB PAGE PUBLIC MEETINGS AREAS OF CONCERN AND CONTROVERSY RESOLUTION OF COMMENTS ON DRAFT LEIS SECTION 5 COORDINATION AND COMPLIANCE WITH ENVIRONMENTAL REQUIREMENTS* U.S. FISH AND WILDLIFE SERVICE RECOMMENDATIONS COMPLIANCE WITH ENVIRONMENTAL LAWS AND REGULATIONS EO 11988, Floodplain Management EO 11990, Protection of Wetlands xxviii

31 5.2.3 EO 12898, Environmental Justice (EJ) Endangered Species Act of Clean Water Act Section 404(b)(1) Evaluation Clean Water Act Section 401 State Water Quality Certification Coastal Zone Management Act Hazardous, Toxic, and Radioactive Waste National Historic Preservation Act ISSUES TO BE RESOLVED UNDER RECOMMENDED PLAN ENVIRONMENTAL CONSIDERATIONS UNDER THE RECOMMENDED PLAN Environmental Impacts of the Recommended Plan Compliance with Environmental Regulations SECTION 6 RECOMMENDATION DESCRIPTION OF THE RECOMMENDED PLAN MRGO ECOSYSTEM RESTORATION PLAN MRGO PLAN INTEGRATION INTO LACPR VIEWS OF THE NON-FEDERAL SPONSOR NON-FEDERAL RESPONSIBILITIES SECTION 7 LIST OF PREPARERS* SECTION 8 LITERATURE CITED* SECTION 9 ACRONYMS AND ABBREVIATIONS* SECTION 10 COMMON AND SCIENTIFIC NAMES OF PLANTS AND ANIMALS* SECTION 11 DISTRIBUTION LIST* SECTION 12 INDEX* Attachment 1: NON-FEDERAL SPONSOR S SELF CERTIFICATION OF FINANCIAL CAPABILITY FOR DECISION DOCUMENTS Attachment 2: DISTRIBUTION LIST* List of Tables Table S.1 Project First Costs... xx Table S.2 Equivalent Annual Benefits and Costs... xx Table S.3 Economic Costs and Benefits of Recommended Plan... xxi Table S.4 Federal and Non-Federal Cost Breakdown... xxii Table 2.1 Alternative 1 Project Construction Costs Table 2.2 Alternative 2 Project Construction Costs Table 2.3 Alternative 3 Project Construction Costs Cost and benefit information used to evaluate the efficiency of each alternative is displayed in Table Table 2.4 Average Annual Benefits and Costs by Alternative Table 2.5 Comparison of Alternatives Based on Four Criteria in Principles and Guidelines Table 3.1 Habitat Change in Project Area xxix

32 Table 3.2 Major Public Recreation Resources within Lake Pontchartrain Basin Table 3.3 MRGO Tonnage by Year (1000s short tons) Table 3.4 MRGO Number of Trips by Vessel Type ( ) Table 3.5 MRGO Number of Trips by Vessel Type (Selected Years) Table 3.6 MRGO Approximate Percentage of Foreign Freight by General DWT Range for Calendar Years 2000, 2002 and Table 3.7 Composition of Tonnage (short tons), 2004 and Table 3.8 Pre-Katrina Employment Table 3.9 Employment by Employers Subject to the Louisiana Employment Security Law Table 3.10 Comparison of Impacts Table 3.11 Checklist for Identification of Cumulative Effects of Future Without Alternative Table 3.12 Checklist for Identification of Cumulative Effects of Alternative Table 3.13 Checklist for Identification of Cumulative Effects of Alternative Table 5.1 Relevant Federal Statutory Authorities and Executive Orders Table 6.1 Project First Costs Table 6.2 Equivalent Annual Benefits and Costs Table 6.3 Economic Costs And Benefits of Recommended Plan Table 6.4 Federal and Non-Federal Cost Breakdown Table 6.5 Existing MRGO Project Features Under Recommended Plan List of Figures Figure S.1 Study Area... iv Figure S.2 Mississippi River-Gulf Outlet Area...viii Figure S.3 Bayou La Loutre Ridge, site of the Total Closure Structure...xxiii Figure 1.1 Project Area... 4 Figure 1.2 Mississippi River-Gulf Outlet Area... 7 Figure 1.3 MRGO Navigation Project Figure MRGO Navigation Project Mile 32 to Mile Figure 1.5 MRGO Navigation Project Mile 15 to Mile Figure 1.6 MRGO Navigation Project Mile -10 to Mile Figure 1.7 Project Features Proposed under Public Law and Public Law ($75M O&M Provision) Figure 2.1 Bayou La Loutre Ridge, site of the Total Closure Structure Figure 3.1 Natural and Scenic Rivers System Appendix A Governor s Letter Appendix B Economics Appendix C Engineering Appendix D Modeling Synopsis Appendices xxx

33 Appendix E Real Estate Appendix F Fish and Wildlife Coordination Act Report Appendix G Calculation of Net Marsh Acres Appendix H Section 404(b)(1) Public Notice Appendix I Section 404(b)(1) Evaluation Appendix J Threatened and Endangered Species Coordination Appendix K Coastal Zone Management Consistency Determination Appendix L Environmental Assessments and Environmental Impact Statements Incorporated by Reference Appendix M Section 106 Consultation Appendix N Section 401 State Water Quality Certification Appendix O Non-Federal Sponsor Letter Appendix P Responses to Comments Received During the Public Review Period xxxi

34 SECTION 1 INTRODUCTION 1.1. FINAL REPORT TO CONGRESS AND LEGISLATIVE ENVIRONMENTAL IMPACT STATEMENT This Final Report to Congress and Legislative Environmental Impact Statement (LEIS) present the findings of a congressionally requested study on the de-authorization of deepdraft navigation on the Mississippi River-Gulf Outlet (MRGO) between the Gulf Intracoastal Waterway (GIWW) and the Gulf of Mexico. This document provides comprehensive documentation of the MRGO Deep-Draft De-authorization Study. Traditionally, a Report to Congress and LEIS would be produced as two separately bound documents. However, a single integrated document meets the requirements of the National Environmental Policy Act (NEPA) and the USACE decision-making process without duplication. The main table of contents includes asterisks for traditional NEPA required chapters and sections to allow ready access for those specifically interested in the NEPA compliance review. The report organization and contents are intended to allow the reader to become familiar with the history of the MRGO Deep-Draft De-authorization Study. The information provided includes study purpose, background, and decision process. The document also describes the direct, indirect, and cumulative environmental effects attributable to alternative plans. Public involvement and agency coordination efforts are documented, as well as technical analyses. The document concludes with a detailed description of the Recommended Plan, which is to construct a total closure structure across the MRGO near Bayou La Loutre in one construction effort. A Legislative Environmental Impact Statement (LEIS) is the detailed statement required by Section 102(2)(C) of the National Environmental Policy Act (NEPA), 42 U.S.C. 4332(2)(C), to be included in a recommendation or report on a legislative proposal to the Congress. Preparation of a LEIS must conform to the requirements of the NEPA implementing regulations, codified at 40 CFR pts , except that (1) there need not be a scoping process; and (2) the LEIS shall be prepared in the same manner as a draft statement, but shall be considered the detailed statement required by statute, 40 CFR (b). 1.2 STUDY AUTHORITY The U.S. Congress has directed the Secretary of the Army, acting through the Chief of Engineers, to develop a plan for de-authorization of deep-draft navigation for the Mississippi River-Gulf Outlet (MRGO) from the Gulf of Mexico to the Gulf Intracoastal Waterway (GIWW). The Emergency Supplemental Appropriations Act for Defense, the Global War on Terror, and Hurricane Recovery, 2006 (Public Law ), reads in part: the Secretary of the Army, acting through the Chief of Engineers, utilizing $3,300,000 of the funds provided herein shall develop a comprehensive plan, at full Federal expense, to de-authorize deep-draft 1

35 navigation on the Mississippi River-Gulf Outlet, Louisiana, extending from the Gulf of Mexico to the Gulf Intracoastal Waterway: Provided further, That, not later than 6 months after the date of enactment of this Act, the Secretary shall submit an interim report to Congress comprising the plan: Provided further, That the Secretary shall refine the plan, if necessary, to be fully consistent, integrated, and included in the final report to be issued in December 2007 for the Louisiana Coastal Protection and Restoration Plan. House Report provides a Congressional conference committee manager s statement accompanying the legislative language further directing that: The plan shall include recommended modifications to the existing authorized current use of the Outlet, including what navigation functions, if any, should be maintained and any measures for hurricane and storm protection. The plan shall be developed in consultation with St. Bernard Parish, the State of Louisiana, and affected Federal Agencies. Congressional direction to prepare a deep-draft de-authorization plan for the MRGO also requires that the plan be fully consistent and integrated with the Louisiana Coastal Protection and Restoration (LACPR) plan. Development of the LACPR plan focuses on identifying a comprehensive plan for flood control, coastal restoration, and hurricane protection in south Louisiana. The future of the MRGO navigation channel is a key decision that affects directions on related projects in the area such as hurricane protection, ecosystem restoration, and navigation. Resolving questions about the future depth and use of the MRGO channel could provide a baseline for developing plans and designs for other related projects. The MRGO de-authorization plan is being integrated into ongoing work to develop and evaluate measures for the LACPR plan. Specific work to integrate the components of the MRGO plan with the LACPR plan includes storm surge modeling, environmental planning, and prioritization. Every effort has been made to accelerate completion of the MRGO Final Report and LEIS in accordance with the Congressional direction found in Title IV, Chapter 3, Section 4304 of the "U.S. Troop Readiness, Veterans' Care, Katrina Recovery, and Iraq Accountability Appropriations Act, 2007" (Public Law ). The MRGO Final Report and LEIS will be transmitted to the Congress as soon as is practicable. The MRGO Final Report and LEIS will also be included in the LACPR Final Report. At the time this report was being released for State and Agency review, the Water Resources Development Act of 2007 (WRDA 2007) became law expanding the scope of the study authority provided by Public Law to include ecosystem restoration. In addition, pursuant to WRDA 2007 Section 7013, upon submission of the final report to Congress, the MRGO from the Gulf of Mexico to Mile 60 at the southern bank of the GIWW is no longer authorized. Section 7013 also authorizes the Secretary of the Army to carry out a plan to close the MRGO and to restore and protect the ecosystem substantially in accordance with the final report subject to the Secretary s determination that the plan is cost-effective, environmentally acceptable, and technically feasible. This 2

36 report preliminarily addresses the ecosystem restoration requirements of WRDA 2007; however, a supplemental report to completely address the ecosystem restoration requirements of WRDA 2007 will be submitted at a later date. WRDA 2007 Section 7013 is provided below in its entirety: SEC MISSISSIPPI RIVER-GULF OUTLET. (a) DEAUTHORIZATION. (1) IN GENERAL. Effective beginning on the date of submission of the plan required under paragraph (3), the navigation channel portion of the Mississippi River-Gulf Outlet element of the project for navigation, Mississippi River, Baton Rouge to the Gulf of Mexico, authorized by the Act entitled An Act to authorize construction of the Mississippi River-Gulf outlet, approved March 29, 1956 (70 Stat. 65) and modified by section 844 of the Water Resources Development Act of 1986 (100 Stat. 4177) and section 326 of the Water Resources Development Act of 1996 (110 Stat. 3717), which extends from the Gulf of Mexico to Mile 60 at the southern bank of the Gulf Intracoastal Waterway, is not authorized. (2) SCOPE. Nothing in this paragraph modifies or deauthorizes the Inner Harbor navigation canal replacement project authorized by that Act of March 29, (3) CLOSURE AND RESTORATION PLAN. (A) IN GENERAL. Not later than 180 days after the date of enactment of this Act, the Secretary shall submit to the Committee on Environment and Public Works of the Senate and the Committee on Transportation and Infrastructure of the House of Representatives a final report on the deauthorization of the Mississippi River-Gulf outlet, as described under the heading INVESTIGATIONS under chapter 3 of title II of the Emergency Supplemental Appropriations Act for Defense, the Global War on Terror, and Hurricane Recovery, 2006 (120 Stat. 453). (B) INCLUSIONS. At a minimum, the report under subparagraph (A) shall include (i) a plan to physically modify the Mississippi River-Gulf Outlet and restore the areas affected by the navigation channel; (ii) a plan to restore natural features of the ecosystem that will reduce or prevent damage from storm surge; (iii) a plan to prevent the intrusion of saltwater into the waterway; (iv) efforts to integrate the recommendations of the report with the program authorized under section 7003 and the analysis and design authorized by title I of the Energy and Water Development Appropriations Act, 2006 (119 Stat. 2247); and (v) consideration of (I) use of native vegetation; and (II) diversions of fresh water to restore the Lake Borgne ecosystem. (4) CONSTRUCTION. The Secretary shall carry out a plan to close the Mississippi River-Gulf Outlet and restore and protect the ecosystem substantially 3

37 in accordance with the plan required under paragraph (3), if the Secretary determines that the project is cost-effective, environmentally acceptable, and technically feasible. 1.3 PROJECT AREA DESCRIPTION The project area is located in southeastern Louisiana in St. Bernard, Orleans, Jefferson, St. Tammany, St. Charles, St. John the Baptist and Tangipahoa Parishes. It covers the Middle and Lower Pontchartrain Basin. The Middle Basin consists of Lake Pontchartrain with its adjacent cities and towns and surrounding wetlands. The Lower Basin consists of Lake Borgne, MRGO, Chandeleur and Breton Sounds and the surrounding wetlands. (Figure 1.1) Figure 1.1 Project Area Southeast Louisiana contains numerous waterways that are important for domestic and international commerce. The Mississippi River is the dominant route in a complex interconnected system. Five ports are located on the Mississippi River between New Orleans and Baton Rouge. These facilities handle inland traffic bringing products from interior states for export. International vessels pick up and deliver goods, materials, and 4

38 passengers. The Mississippi River is connected to other waterways through locks at Harvey Canal, Algiers, and the Industrial Canal. These locks provide transit points for traffic movements on the GIWW. In addition, the lock at the Industrial Canal connects to the MRGO deep-draft channel, the shallow-draft GIWW, and into Lake Pontchartrain. Another connection is available near the mouth of the Mississippi River at Baptiste Collette Bayou which provides a link to the MRGO across Breton Sound (see Figure 1.2). 1.4 BACKGROUND ON THE MRGO The MRGO provides a shorter navigation route from the Gulf of Mexico to the Port of New Orleans tidewater facilities compared to using the Mississippi River to access the port. Construction of the MRGO channel began in 1958 and was completed in The channel extends from the Inner Harbor Navigation Canal (IHNC) in New Orleans to the 38-foot depth contour in the Gulf of Mexico (see Figure 1.2). The stretch contiguous with the GIWW is the called the GIWW Reach (mile 66-60). Where the channel diverts from the GIWW and runs through wetlands for 37 miles is known as the Inland Reach (mile 60-23). The 23 miles through Breton and Chandeleur Sounds is called the Sound Reach (mile 23-0). The portion in the Gulf of Mexico is the Bar Channel (mile 0 to -9.4). All reaches of the MRGO navigation channel are authorized as a 36-foot deep, 500-foot bottom width waterway with the exception of the Bar Channel which is authorized as a 38-foot deep, 600-foot bottom width waterway. MRGO channel construction was authorized by a March 29, 1956 Act of Congress (Public Law ) as a modification to the existing project for Mississippi River, Baton Rouge to the Gulf of Mexico. The Act authorized construction of the MRGO Project substantially in accordance with the recommendation of the Chief of Engineers contained in House Document No. 245, 82 nd Congress. In addition to recommending construction of the channel, the Chief of Engineers recommended the construction of (1) protective jetties at the entrance to the channel from the Gulf of Mexico; (2) a permanent retention dike through Chandeleur Sound and a wing dike along the islands as required; (3) a turning basin with a project depth of 36 feet Mean Low Gulf (MLG), a width of 1,000- feet and a length of 2,000 feet at the junction of the new channel and the Inner Harbor Navigation Canal; and (4) a highway bridge with approaches to carry Louisiana State Highway 61 over the channel. All of these features were constructed, with the exception of the permanent retention dike through Chandeleur Sound and the wing dike along the islands. Public Law also authorized replacement of the existing IHNC Lock when economically justified. In 1968, the River and Harbor Act (Public Law ) authorized the Michoud Canal Project as a modification of the MRGO Project. The Michoud Canal Project authorized a deep-draft navigation channel in the GIWW and Michoud Canal by enlargement to a depth of 36 feet over a bottom width of 250 feet from the MRGO channel to and including a turning basin 800 feet square at the north end of the Michoud Canal. The Michoud Canal Project was constructed; however, the IHNC Lock has not yet been replaced. 5

39 The Federal government is responsible for constructing, operating, and maintaining all features of the MRGO Project, including the Michoud Canal Project, with the exception of the highway bridge and its approaches, which is owned, operated, and maintained by non-federal entities. The Port of New Orleans, the non-federal project sponsor, is responsible for furnishing free of cost to the Federal government all lands, easements, rights-of-way, relocations, and disposal areas (LERRDs) required for construction and maintenance of the MRGO Project. When the MRGO Project was built approximately 3,150 acres of marsh, 100 acres of wetland forest and 830 acres of shallow open water were converted to the deep water navigation channel between the GIWW and the Gulf of Mexico. The dredge material from channel construction was placed in a disposal area that was about 4,000 feet wide in most places and immediately southwest of the channel. The material in this disposal area was piled about 10 feet high and covered about 12,440 acres of marsh, 1,410 acres of wetland forest and 3,920 acres of shallow open water (USACE 1999). It is estimated that habitat shifts caused by saline waters brought in by the MRGO might have caused the following in areas adjacent to the MRGO: 3,350 acres of fresh/intermediate marsh and 8,000 acres of cypress swamp converted to brackish marsh and 19,170 acres of brackish marsh and swamp became saline marsh (USACE 1999). Bank erosion along the MRGO has been estimated to occur at rates of between 27 and 38 feet per year on the Inland Reach (USACE 2004). Between 1964 and 1996, 5,324 acres of marsh have been lost adjacent to the MRGO channel (mile 66 to 21). Operation and maintenance of the MRGO channel has required the construction of additional project features. Bank stabilization measures, also called foreshore protection, have been constructed along several reaches of both the north and south banks of the GIWW and Inland Reaches to prevent sloughing of the bank into the channel and to protect adjacent wetlands and levees. Bank stabilization measures exist in the following locations: 1) MRGO north bank (Miles 66-60, Miles , Miles 43 41, Miles , Miles , Miles ), and 2) MRGO south bank (Miles 66-60, Miles 60-47, Articulated Concrete Mattress (ACM) Miles and 37.3 to 36.5). In addition, Miles 23.2 to 20.8 of the north and south jetties provide foreshore protection for adjacent wetlands. 6

40 Figure 1.2 Mississippi River-Gulf Outlet Area. Many disposal sites have been designated for maintenance of the MRGO Project. These include numerous upland disposal sites and beneficial use sites for wetlands restoration and nourishment. Dredged material was used beneficially from 1985 to An average of about 16 acres per year was created in the Inland Reach. Shallow open water areas on the north and south side of the jetties have been used for the placement of dredged material in a manner conducive to wetland creation. An average of about 17 acres per year was created behind the jetties. Dredged material has also been placed at an offshore feeder berm to nourish Breton Island and in shallow open water immediately adjacent to Breton Island to restore barrier island habitat destroyed by erosion and storms. About 21 acres per year was created on Breton Island. In the area behind the south jetty, LDNR has required disposal to be placed as point sources in an effort to create marsh. LDNR has also requested that point disposal areas be used at two-mile intervals across Breton Sound to attempt to create islands. These areas have been used, but no islands have been created. There is also an approximately 5,000 acre EPA-designated Ocean Dredged Material Disposal Site (ODMDS) located parallel to and south of the channel from mile 4 to mile -10. Only the portion from mile -4 to mile -10 has been recently used for disposal. 7

41 The MRGO Project features which have been discussed in the paragraphs above are illustrated on Figures 1.3, 1.4, 1.5 and 1.6. Direct costs of construction, operation, and maintenance of the MRGO have been funded by the Federal government. These direct costs have totaled over $580 million since The average annual operations and maintenance expenditures for the MRGO were $12.5 million (in 2000 dollars). However, following tropical storms and hurricanes, supplemental expenditures have often been required to return the MRGO to the authorized dimensions. Since 1998, the $12.5 million has not allowed for dredging of the channel to its full-authorized dimensions. The GIWW Reach has not been dredged since From 1998 to 2005, the Inland Reach was maintained to a minimum 300-foot bottom width; the Sound Reach to a minimum 450-foot bottom width; and the Bar Channel to a minimum 500-foot bottom width. There has been no channel maintenance dredging in any reach of the MRGO since Hurricane Katrina in Sections of the MRGO experienced severe shoaling during Hurricane Katrina, leading to a current controlling channel depth of approximately 22 feet. The estimated cost to return the channel to authorized dimensions (36 feet deep by 500 foot bottom width; 38 feet deep by 600 foot bottom width in Bar Channel) is $130,444,870 based on October 2006 price levels. However, as discussed previously, for the past several years prior to Hurricane Katrina the channel has been maintained to reduced dimensions in some reaches. The estimated cost to return the channel to 36 feet deep by 300 foot bottom width in all reaches is $62,380,000 based on October 2006 price levels. For this de-authorization study, although no current plans exist to dredge the MRGO, it is important to estimate these costs for comparison purposes in evaluating future alternatives for modifying the channel. After Hurricane Katrina, the U.S. Congress passed two laws providing funds for emergency repairs or authorizing other actions related to the MRGO navigation channel. Chapter 3, under Division B of Title I of the Department of Defense, Emergency Supplemental Appropriations to Address Hurricanes in the Gulf of Mexico, and Pandemic Influenza Act, 2006 (Public Law ) provided $75,000,000 for operation and maintenance (O&M) activities along the MRGO. Section 2304 of Chapter 3 in Title II of the Emergency Supplemental Appropriations Act for Defense, the Global War on Terror, and Hurricane Recovery, 2006 (Public Law ) clarified that these funds were to be used for "the repair, construction or provision of measures or structures necessary to protect, restore or increase wetlands, to prevent saltwater intrusion or storm surge." The USACE currently plans to use these funds for the following project features (see Figure 1.7): - Shoreline protection along Lake Borgne from Doullut s Canal to Jahncke s Ditch (under construction, utilizes some funds from Public Law ) - - Shoreline protection along MRGO north bank Miles (proposed, NEPA compliance complete) - - Shoreline protection along Lake Borgne flanking the opening of Bayou Bienvenue (proposed, NEPA compliance incomplete) 8

42 - Shoreline protection along Lake Borgne flanking the opening of Bayou Dupre (proposed, NEPA compliance incomplete) - Shoreline protection along Lake Borgne west of Shell Beach (proposed, NEPA compliance incomplete) - Marsh creation through dedicated dredging within the Golden Triangle (proposed, NEPA compliance incomplete) - Marsh creation through dedicated dredging at Shell Beach (proposed, NEPA compliance incomplete) In addition to providing funds to develop a comprehensive plan to de-authorize deep-draft navigation on the MRGO, Public Law authorized and provided $350 million for construction of enhanced hurricane protection for the IHNC, and $170 million to armor critical areas of the levee system. Efforts to plan and design these items are underway. 9

43 Figure 1.3 MRGO Navigation Project 10

44 Figure MRGO Navigation Project Mile 32 to Mile 66 11

45 Figure 1.5 MRGO Navigation Project Mile 15 to Mile 50 12

46 Figure 1.6 MRGO Navigation Project Mile -10 to Mile 15 13

47 Figure 1.7 Project Features Proposed under Public Law and Public Law ($75M O&M Provision) 14

48 1.5 STUDY PURPOSE AND NEED The purpose of the study is to provide to Congress a comprehensive plan to de-authorize deep-draft navigation on the MRGO from the GIWW to the Gulf of Mexico. As requested in the authorizing legislation, an Interim Report to Congress was submitted in December The Interim Report to Congress stated that preliminary analysis indicated that the best plan was to close the MRGO from the GIWW to the Gulf of Mexico to both deep- and shallow-draft navigation. The MRGO comprehensive deauthorization plan must be consistent with ongoing design and planning efforts related to storm protection and coastal restoration and long-term planning related to the LACPR. In terms of design and planning, this MRGO de-authorization study and subsequent Congressional action defines the navigation future of the MRGO and thus enables other related projects to move forward with more certainty. The study also comports with the Chief of Engineer s 12 Actions for Change calling for effectively implementing comprehensive systems approaches to water resources problems. In a letter dated June 2, 2006 (see Appendix A), Governor Blanco of the State of Louisiana made a request for a plan for closure, restoration of the extensive wetlands lost as a direct result of the MRGO, and the integration of this closure into the comprehensive hurricane protection plan. The USACE and State of Louisiana are partners on efforts to develop LACPR and the state is also a key stakeholder in the development of the MRGO de-authorization study. 1.6 STUDY GOALS AND OBJECTIVES The goals and objectives for the MRGO deep-draft de-authorization study are derived entirely from the Congressional authorizing language and accompanying committee report. Those goals and objectives are: Develop a comprehensive plan to de-authorize deep-draft navigation on the MRGO channel from the GIWW to the Gulf of Mexico Evaluate any navigation functions that should be maintained on the MRGO channel Identify measures for hurricane and storm damage reduction Refine the plan to be fully integrated and consistent with the Louisiana Coastal Protection and Restoration (LACPR) Final Report to Congress 1.7 PRIOR STUDIES, REPORTS AND PROJECTS Numerous studies, reports and projects have been conducted in the MRGO area. These studies represent the allocation of significant resources towards research provided by the Federal and state government and by private, non-profit foundations. Many of the recommendations have been enacted, such as bank stabilization projects. In this section, these studies are briefly summarized, as well as some of the Federal legislative actions that have made Federal funding possible. 15

49 1.7.1 Mississippi River and Tributaries (MR&T) This is a comprehensive project for flood control on the lower Mississippi River below Cape Girardeau, Missouri. The project was authorized as a result of the 1927 flood of the lower Mississippi River. The MR&T has four major elements: levees, floodways, channel improvement and stabilization, and tributary based improvements. The MR&T system controls and confines the river system before it reaches the coastal area. Several major outlets to the main stem of the river exist for the purposes of flood control during flood stages. The IHNC lock connects the Mississippi River to the IHNC, the MRGO, and Lake Pontchartrain Gulf Intracoastal Waterway (GIWW) The GIWW was authorized and construction was begun in the 1920 s. The GIWW traces the U.S. coast along the Gulf of Mexico from Apalachicola Bay near Carrabelle, Florida to the Mexican border at Brownsville, Texas. From its intersection with the Mississippi River, the waterway extends eastward for approximately 376 miles and westward for approximately 690 miles. The GIWW and MRGO intersect and run contiguously from the Michoud area to the IHNC Bayous La Loutre, St. Malo and Yscloskey, 1945 The River and Harbor Act of 26 August 1937, modified 2 March 1945 provides for a channel 5- by 40-feet deep from deep water in Lake Borgne to the shore line at the mouth of Bayou Yscloskey; a channel 6- by 40-feet deep from deep water in Lake Borgne through Bayous St. Malo, La Loutre and Eloi to deep water in Lake Eloi; a channel 5- by 30-feet in Bayou La Loutre between Hopedale and Bayou St. Malo. The length of improvements is 30 miles. The MRGO crosses Bayou La Loutre near Hopedale, Louisiana MRGO, Michoud Canal, Louisiana Project, 1968 This project was authorized by the River and Harbor Act of 1968 (Public Law ), substantially in accordance with the recommendations of the Chief of Engineers in Senate Document No. 97, 90 th Congress. The Chief of Engineers recommended the modification of the existing MRGO Project to provide a deep-draft navigation channel in the GIWW and Michoud Canal by enlargement to a depth of 36 feet over a bottom width of 250 feet from the MRGO channel to and including a turning basin 800 feet square at the north end of the Michoud Canal Inner Harbor Navigation Canal Lock Replacement Project, 1956 The IHNC and the IHNC lock were built by the Board of Commissioners for the Port of New Orleans during the late 1910s and early 1920s and placed into service in May The dimensions of the canal were 200 feet wide x 20 feet deep. Subsequent to the construction of the MRGO, sections of the IHNC were deepened to handle deep-draft ships and the Port of New Orleans constructed a container terminal on the IHNC. Because of the size of the existing IHNC lock, deep-draft shipping can use only the MRGO to access these facilities. The IHNC lock has dimensions of 31.5 feet deep x 75 feet wide x 640 feet long. During World War II, the Federal government leased the IHNC lock and assumed its maintenance and operation. The Federal government acquired the existing lock in Public Law originally authorized construction of a new 16

50 lock and connecting channels or replacement of the existing IHNC lock when economically justified. The Water Resources Development Act (WRDA) of 1986 (Public Law ) reauthorized replacement of the lock and established cost share requirements for the project. The WRDA of 1996 (Public Law ) authorized implementation of a Community Impact Mitigation Plan for the project. An Evaluation Report and final EIS were prepared in The replacement lock will be 110 feet wide x 36 feet deep x 1,200 feet long. The construction period is estimated at 12 years. The cost (in October 2004 price levels) is $764 million. The new lock has not been funded to capability levels since The project is presently on hold while a supplemental EIS is prepared Lake Pontchartrain and Vicinity, Louisiana, Hurricane Protection Project, 1965 This project was authorized by Section 204 of the Flood Control Act of 1965 (Public Law , as amended), substantially in accordance with the recommendations of the Chief of Engineers in House Document No. 231, 89 th Congress. The project currently provides for enlargement of hurricane protection levees along Lake Pontchartrain in Orleans, Jefferson, and St. Charles Parishes and in portions of Orleans and St. Bernard Parishes between the Mississippi River and the MRGO. The Chalmette Loop Levee and Citrus Back Levee segments of this project run parallel to the MRGO. The Act also authorized construction of the Seabrook Lock where the IHNC enters Lake Pontchartrain. Operation and maintenance of the Lock was to occur under the MRGO Project, but the Lock was never constructed Mississippi River Outlets, Venice, Louisiana, 1968 Mississippi River - Additional Navigation Outlets in the Vicinity of Venice, Louisiana was authorized by the River and Harbor and Flood Control Act of 1968 (Public Law ) to enlarge the existing channels of Baptiste Collette Bayou and Grand-Tigre Passes to provide a 14 feet depth over a bottom width of 150 feet, with entrance channels in open water 16 feet deep over a bottom width of 250 feet. Jetties were authorized to the -6 foot contour. Channel construction was completed in 1978 and jetty construction completed in Baptiste Collette Bayou, in conjunction with the Mississippi River and MRGO, is an alternate route for shallow-draft traffic when the IHNC lock is closed MRGO St. Bernard Parish, Louisiana, Reconnaissance Report, February 1988 The USACE conducted a reconnaissance study of bank erosion and erosion-related problems. Economically justified and environmentally acceptable plans were identified and recommended for further detailed studies. No further action occurred Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA), 1990 The Coastal Wetlands Planning, Protection and Restoration Act (Public Law ) Program provides funding for projects that restore the coastal ecosystem. One such project, the MRGO Disposal Area Marsh Protection was approved in 1993 to repair damage to the back dike of the disposal area to preserve approximately 755 acres of wetland. The project was completed in 1999 and at a cost of $342,611. Another project, the Lake Borgne and MRGO Shoreline Protection was approved in 2003 to construct an 18,500-linear-foot rock dike along the Lake Borgne shoreline, and a 14,250-linear-foot rock dike along the north 17

51 bank of the MRGO between Doullut s Canal and Lena Lagoon to preserve approximately 266 acres of wetland. Funding of $1.4 million was approved, and the total estimated cost of the project is $25,100,000. Construction for that project has not been approved to date. Additional coastal restoration projects involving shoreline protection and hydrologic restoration have been approved and constructed in the area MRGO North Bank Foreshore Protection Evaluation, 1996 This study concluded that providing hardened bank protection along portions of the north bank of the MRGO reduces shoaling rates, thereby decreasing the overall maintenance costs of the channel. The recommended plan was to construct, under authority of the O&M program, hardened bank protection in those reaches identified as being critical because of their high shoaling rates and the imminent loss of the buffering marsh between the MRGO and Lake Borgne Coast 2050: Toward a Sustainable Coastal Louisiana, 1998 The Louisiana Coastal Wetlands Conservation Task Force and the Wetlands Conservation & Restoration Authority prepared this plan for the Louisiana Department of Natural Resources. It addressed the problem of depletion of coastal land across Louisiana, including the particular problems of increases in salinity and erosion attributed to the MRGO, and recommended ecosystem management strategies designed to restore wetlands and prevent continued deterioration. Ecosystem management strategies recommended in the plan in the vicinity of the MRGO are: Closure of the MRGO when alternative container port facilities on the Mississippi River are prepared; Stabilization of the entire north bank of the MRGO using dredged material behind rock dikes along a 37-mile reach; Constriction of breaches in the marshes between the MRGO and Lake Borgne, to reduce salinity in Lake Borgne and the Biloxi Marshes; Construction of a sill at Seabrook, to improve salinity in Lake Pontchartrain Further study of the 2,000-5,000 cfs freshwater diversion project at the Violet Canal; Use of dredged material from the MRGO to create marshes in South Lake Borgne, the Biloxi Marshes, and Eloi Bay MRGO Reevaluation Study 2002 In June 1999, pursuant to authority of Section 216 of Public Law , the USACE- MVN requested and received reprogrammed funds to initiate a reevaluation study of the MRGO based on three factors: 1. The possibility that the Port of New Orleans might move some of its facilities from the IHNC area to the Mississippi River (Millennium Port Plan); 18

52 2. The environmental community and local interests characterized the MRGO as an environmental disaster; and 3. Efforts to ameliorate some of the environmental effects of the MRGO using O&M funds were inadequate. In June 2000, the House Committee on Appropriations (House Report , PL ) provided funds for investigating the future of the MRGO. The study was not completed due to additional Congressional guidance and authority provided after Hurricane Katrina Environmental Assessment for the Lake Borgne Shoreline Protection Project This USEPA document for CWPPRA project number PO-30 provided an overview of the impacts and/or benefits resulting from the installation of shoreline protection features in Lake Borgne. The goal of this project was to help preserve the existing wetland land bridge between Lake Borgne and the MRGO and thus prevent the coalescence of the two water bodies by constructing shoreline protection features along a total of 5.3 miles of the southern Lake Borgne shoreline near Bayou Dupre and near Shell Beach Ecological Review, Lake Borgne and MRGO Shoreline Protection This USACE/LDNR ecological review for CWPPRA project number PO-32 evaluated project biotic benefits, goals and strategies prior to construction authorization. This evaluation utilized monitoring and engineering information, as well as applicable scientific literature to assess whether or not, and to what degree, the proposed project features would cause the desired ecological response. The goal of this project was to preserve the existing marsh land bridge between Lake Borgne and the MRGO and thus prevent the coalescence of the two water bodies Continuing Authorities Program Section 204 of the Water Resources Development Act (WRDA) 1992, is a "continuing authority" that authorizes the Secretary of the Army to plan, design, and implement certain ecosystem restoration measures, subject to specified cost sharing, without additional project specific Congressional authorization. Section 204 authorizes the beneficial use of dredged material in connection with construction or maintenance dredging of an authorized navigation project. Projects performed under Section 204 on the MRGO include the placement of dredged material from miles 14 to 12 adjacent to the south jetty for wetland creation and the placement of dredged material from mile -2 to -4 on Breton Island for barrier island restoration Louisiana Coastal Area Ecosystem Restoration Study (LCA 2004) The USACE and the State of Louisiana prepared this study to identify the most critical ecological needs of the coastal area and to describe alternative restoration strategies. The MRGO was identified as one of the five specific areas with significant needs, and environmental restoration costs for an MRGO near-term plan were estimated at $121,736,000 (2004 dollars). The LCA Plan recommended construction of rock breakwaters along 23 miles of the north bank of the MRGO, and 15 miles of the southern 19

53 shore of Lake Borgne. This construction would address the anticipated loss of 6,350 acres of marsh over a 50-year period of analysis. The Chief of Engineers and the Assistant Secretary of the Army for Civil Works approved and transmitted the LCA Plan to the Administration and Congress. The plan is awaiting congressional action on a Water Resources Development Act bill for authorization Second Emergency Supplemental Appropriations Act to Meet the Immediate Needs Arising from the Consequences of Hurricane Katrina, 2005 (Public Law ) Adopted by Congress on September 2, 2005, following Hurricane Katrina, this law provided emergency supplemental funding to repair damage to flood control and hurricane shore protection projects. A portion of this funding was allocated to rebuilding the hurricane protection levee located on a portion of the MRGO dredged material disposal area between Bayou Bienvenue and Verret, Louisiana Department of Defense, Emergency Supplemental Appropriations to Address Hurricanes in the Gulf of Mexico, and Pandemic Influenza Act, 2006 (Public Law ) and Emergency Supplemental Appropriations Act for Defense, the Global War on Terror, and Hurricane Recovery, 2006 (Public Law ) The Department of Defense, Emergency Supplemental Appropriations to Address Hurricanes in the Gulf of Mexico, and Pandemic Influenza Act, 2006 (Public Law ) provided $75,000,000 for operation and maintenance activities along the MRGO. The Emergency Supplemental Appropriations Act for Defense, the Global War on Terror, and Hurricane Recovery, 2006 (Public Law ) clarified that the funds were to be used for "the repair, construction or provision of measures or structures necessary to protect, restore or increase wetlands, to prevent saltwater intrusion or storm surge." An EIS for this work is being prepared. This operation and maintenance activity is called Mississippi River - Gulf Outlet, Louisiana, and Lake Borgne Wetland Creation and Shoreline Protection. In addition to providing funding to develop a comprehensive plan to de-authorize deepdraft navigation on the MRGO, Public Law provided nearly $4 billion for levee improvements and flood control projects in the New Orleans area. This appropriation included $1,584 million to reinforce or replace floodwalls, $495.3 million for levee projects, $350 million for construction of enhanced hurricane protection on the IHNC, and $170 million to armor critical areas of the levees Coastal Impact Assistance Program, 2006 The Coastal Impact Assistance Program (CIAP) was authorized by Section 384 of the Energy Policy Act of This federally funded program assists oil and gas producing coastal states and their political subdivisions in mitigating the impacts from Outer Continental Shelf (OCS) oil and gas production. There are two Tier One CIAP projects in the project area: Central Wetlands Assimilation (treated sewerage pumped into wetlands) and Orleans Land Bridge Shoreline Protection and Marsh Creation. The Lake Borgne Shoreline Protection is a Tier Two project. 20

54 Louisiana Coastal Protection and Restoration (LACPR), 2006 This study by the USACE for the U.S. Congress includes the analysis and design of hurricane risk reduction, coastal restoration, and flood control measures. A Preliminary Technical Report was submitted to Congress in July The final study will evaluate different alignments of structural measures, such as floodgates, floodwalls, and levees, to compare relative reduction of risk of flooding and storm surge, including the possibility of structural measures affecting the MRGO. The final study will also evaluate nonstructural measures, such as elevating homes. In addition, it will propose various wetland restoration projects and highlight the role of wetlands in coastal risk reduction Integrated Ecosystem Restoration and Hurricane Protection: Louisiana s Comprehensive Master Plan for a Sustainable Coast, 2007 The State of Louisiana s Master Plan calls for construction of a closure structure at Bayou La Loutre that will restore the integrity of the Bayou La Loutre ridge. This will affect both the shallow-draft and deep-draft navigation industries, and it may have unintended consequences for adjacent landowners Environmental Assessments and Environmental Impact Statements The USACE-MVN has prepared many Environmental Assessments (EAs) and Environmental Impact Statements (EISs) to evaluate potential impacts of project specific proposed actions in and around the MRGO. These EAs and EISs were prepared in accordance with the NEPA of 1969 and the Council on Environmental Quality (CEQ) Regulations (40 CFR ), as reflected in the USACE Engineering Regulation, ER These documents, as listed in Appendix L, are hereby incorporated into this LEIS by reference. 1.8 THE MRGO AND STORM SURGE Numerous people believe that the Inland Reach of the MRGO exacerbates storm surges in the region and that the MRGO was responsible for flooding of both St. Bernard and Orleans Parishes during Hurricanes Betsy and Katrina. However, several studies described below indicate that this was not the case (see Appendix D). A 1966 study (Bretschneider and Collins, 1966) examined six different storm scenarios using one-dimensional numerical modeling, and concluded that Hurricane Betsy, which occurred in 1965 during the construction of the MRGO, would have produced the same storm surge elevations with or without the MRGO. In 2003, a study was completed using two-dimensional Advanced Circulation (ADCIRC) modeling for storm surge (USACE 2003). Nine different scenarios were modeled, both with and without the MRGO (shallow marsh in place of the channel). The model runs demonstrated that the maximum difference in storm surge with and without the MRGO was just over 6 inches. Following Hurricane Katrina, the Interagency Performance Evaluation Task Force (IPET) studied the New Orleans hurricane protection systems, storm surge, performance of flood protection measures, and the consequences of the hurricane (USACE 2007a and USACE 21

55 2007b). The IPET found that the MRGO Inland Reach had little influence on flooding in St. Bernard Parish during Hurricane Katrina, because when the marshes surrounding the MRGO are inundated, the water conveyed through the channel is a relatively small part of the total. The IPET Report states during Katrina, the MRGO was far from the hurricane highway moniker with which it has been branded. The report found that high surge and high, long-period waves overtopped the MRGO levees well before the hurricane made landfall, and that the high velocities of water moving over the levees caused scouring and breaching of levees along the MRGO (USACE 2007b). The IPET does state that While the simulations clearly show that Reach 2 [Inland Reach] of the MRGO does not significantly influence the development of storm surge in the region for large storm events, Reach 1 (the combined GIWW/MRGO section) and the IHNC, together, provide a hydraulic connection between Lake Borgne and Lake Pontchartrain. As a result of this connection, the storm surge experienced within the IHNC and Reach 1 (GIWW/MRGO) is a function of storm surge in both Lakes; a water level gradient is established within the IHNC and Reach 1 [GIWW Reach] that is dictated by the surge levels in the two lakes. This is true for both low and high storm surge conditions. To prevent storm surge in Lake Borgne from reaching the IHNC or GIWW/MRGO sections of [the] waterway, flow through the Reach 1 [GIWW Reach] channel must be dramatically reduced or eliminated, either by a permanent closure or some type of structure that temporarily serves to eliminate this hydraulic connectivity. The presence of an open channel is the key factor (USACE 2007b). Flow through the GIWW Reach of the MRGO is being addressed through efforts to provide comprehensive hurricane and storm protection through the Lake Pontchartrain and Vicinity Hurricane Protection project 100-year protection effort. In 2006, the USACE analyzed the Southeast Louisiana Hurricane Protection System and found that [t]he southeast trending leg of the Mississippi River-Gulf Outlet (MRGO) had little influence on the water levels in the IHNC during Katrina (USACE 2007a). This conclusion was reached after comparing the results of ADCIRC models runs, assuming the MRGO channel existed in its pre-katrina conditions, and then assuming that the MRGO did not exist. A 2006 study by the Louisiana Department of Natural Resources also evaluated the impact of the MRGO on storm surge using ADCIRC modeling. This study considered seven different scenarios. The conclusions were that the MRGO does not contribute significantly to peak storm surge during severe storms where the surrounding wetland system is overwhelmed with water, and that closure would not provide significant, direct mitigation of severe hurricane storm surge. However, closure of the MRGO may, according to the LDNR study, modestly delay the onset of surge in a few locations and would significantly reduce storm surge scour velocities at some locations (LDNR 2006). Studies also demonstrated that the most noticeable effect of the MRGO occurs for small surge events, where the marsh areas are not completely inundated (USACE 2007b; LDNR 2006). As part of LACPR, further storm surge modeling analyses are underway to consider scenarios with new structural flood protection features, such as levees and 22

56 floodgates. Solutions to concerns regarding the impact of storm surge that the public has posed include barrier construction, such as floodgates at some points along the MRGO, and partially or completely filling in the channel. 23

57 SECTION 2 FORMULATION OF ALTERNATIVE PLANS This chapter includes a discussion of the collaborative planning process, development of alternatives in the Interim Report to Congress, the future without de-authorization, alternatives eliminated from further study, alternatives evaluated in detail, a comparison of these alternatives, rationale for choosing the Recommended Plan, a brief description of that plan, and how it will be integrated into the LACPR process. In order to ensure that sound decisions are made, the USACE plan formulation process requires a systematic and repeatable approach. The Economic and Environmental Principles for Water and Related Land Resources Implementation Studies and The Economic and Environmental Guidelines for Water and Related Land Resources Implementation Studies (Planning Guidance Notebook, ER ) describe the USACE study process and requirements. Alternatives were formulated to minimize cost associated with the disposition of the de-authorized project. These alternatives were also evaluated against the following four criteria: Completeness - the extent to which a given alternative plan provides and accounts for all necessary investments or other actions to ensure the realization of the planned effects. Effectiveness - the extent to which an alternative plan alleviates the specified problems and achieves the specified opportunities. Efficiency - the extent to which an alternative plan is the most cost-effective means of alleviating specified problems and realizing the specified opportunities, consistent with protecting the Nation s environment. Acceptability - the workability and viability of the alternative plan with respect to acceptance by state and local entities and the public and compatibility with existing laws, regulations, and public policies. Plan formulation did not consider stand alone ecosystem restoration measures as this was not included in the study authority. However, to provide a comprehensive plan, formulation incorporated consideration of the ecosystem restoration advantages that might be provided by measures that limit channel access. 2.1 COLLABORATIVE PLANNING In response to Congressional direction to develop a comprehensive MRGO deep-draft deauthorization plan, the USACE established a strategy for developing the Interim and Final Reports. Federal, state and local government parties, environmental groups, landowners, navigation interests, other organizations, and individuals were invited to assist in preparation of the reports. This approach is a sound business process for problem solving and is consistent with USACE guidance in EC (Planning in a Collaborative Environment) and ER (Planning Guidance Notebook). 24

58 A series of public stakeholder forums were held which included technical presentations and open discussions on topics including wetlands, navigation, storm protection, and the local economy. Each stakeholder group was asked to identify their own plans for deauthorization of the MRGO, environmental restoration measures in the vicinity of the MRGO, and hurricane protection plans. Several stakeholder groups prepared such plans. A public meeting was held on October 28, 2006 at the University of New Orleans and involved an open house where stakeholder groups were offered display space to present their plans. More than 150 people attended the public meeting, which included a formal presentation of the study process and scope from the USACE and an open comment period for public statements from citizens, organizations, and elected officials. Public comments made in this meeting were evaluated in plan formulation for the Interim Report to Congress. Through the collaborative process several consensus measures emerged that were supported by many stakeholders. However, the different stakeholders could not agree on a single measure, plan, or sequence of measures to close the channel. Their recommendations varied from total closure to a sector gate with a draft of 28 feet. Many of the measures from the stakeholder plans were incorporated into the Interim Report to Congress. Collaborative planning continued after the submittal of the Interim Report to Congress and that approach remains a key component of the preparation of the Final Report to Congress and LEIS. For further description of the proposed stakeholder plans, see Section 4. A public information meeting was held on May 19, 2007 at Nunez Community College in Chalmette, Louisiana. The meeting offered attendees an opportunity to view a series of posters presented by the USACE on the elements of the study. In addition, various stakeholders displayed information and interacted with the meeting attendees. More than 100 attendees listened to a formal presentation regarding the alternatives evaluated in detail and the Recommended Plan. Following the presentation, attendees had the opportunity to ask questions. All attendees were made aware of the study schedule and process and invited to continue to participate. Input from the public, stakeholders, and agencies received through the collaborative planning process provided significant information which was used by the USACE to assess the acceptability of alternatives. Agencies were not approached to assume responsibility for implementing components of the Recommended Plan other than to coordinate required environmental compliance actions and the removal of aids to navigation. Interagency support of the Recommended Plan has been expressed (see Appendix P). Given the nature of the Recommended Plan, few if any opportunities exist for other agencies to implement plan components. The LACPR effort, of which the MRGO Final Report and LEIS is a part, will likely result in recommendations for sharing implementation responsibilities across agencies. 25

59 2.2 DEVELOPMENT OF ALTERNATIVES FOR INTERIM REPORT TO CONGRESS For the Interim Report to Congress, a USACE technical team evaluated potential modifications to the current uses of the navigation channel with the intent of determining if any uses should be maintained. The evaluation included information presented in the stakeholder meetings, data gathered through a survey of maritime businesses, and government records of annual channel utilization. A broad suite of initial alternatives was identified for development of the deep-draft de-authorization plan. The alternatives presented in the Interim Report to Congress include: Interim Report Alternative 1 Maintain a shallow-draft MRGO navigation channel. Alternative 1a Maintain a shallow-draft navigation channel without a structure; Alternative 1b Construct a salinity control weir at Bayou La Loutre; Alternative 1c Construct a salinity control gate at Bayou La Loutre (normally closed); Alternative 1d Construct a storm protection gate at Bayou La Loutre (normally open). All of the shallow-draft MRGO navigation alternatives would require maintenance dredging of a 12-foot deep by 125-foot wide channel to match the authorized dimensions of the GIWW. Interim Report Alternative 2 - Close the MRGO channel to deep-draft and shallowdraft vessels. Closure of the MRGO to all vessel traffic could be realized by blocking the channel via any of the following variations: Alternative 2a Construct a total closure structure across the MRGO at Bayou La Loutre; Alternative 2b Restore both banks of Bayou La Loutre across the MRGO at Hopedale, Louisiana; or Alternative 2c Fill in the entire MRGO channel from the GIWW to the Gulf of Mexico. Interim Report Alternative 3 - Cease all MRGO operations and maintenance activities (dredging, jetty repairs, and navigation aids). If Congress chooses to discontinue all activities related to maintaining the MRGO, several relic project features would need to be addressed. These features include navigation aids such as buoys and lights and the offshore jetties located in Breton and Chandeleur Sounds. Development of a comprehensive de-authorization plan should include disposal of these relic features. There would be no more beneficial use of dredged material. The alternatives developed for the Interim Report to Congress are explained in detail below: Interim Report Alternative 1a - Maintain a Shallow-Draft MRGO Navigation Channel Without a Structure Under Alternative 1a, the MRGO would be maintained for commercial and recreational shallow-draft navigation only with a depth and width of 12 feet by 125 feet for the Inland and Sound Reaches. This alternative was developed to allow continued shallow-draft navigation. It is likely to have only a very minimal effect on reducing salinity or storm 26

60 surge in a tropical storm event. The only environmental benefit could be removal of deep-draft vessels from the channel which could significantly reduce bank erosion. Interim Report Alternative 1b Construct a Salinity Control Weir at Bayou La Loutre Under Alternative 1b, a weir would be constructed just south of Bayou La Loutre to allow passage of shallow-draft vessels. The MRGO would be constricted at the weir to 125-feet wide by 14 feet deep. This alternative was developed to allow continued shallow-draft navigation and to reduce salinity above the structure which could provide environmental benefits. Removal of deep-draft vessels could significantly reduce bank erosion. Interim Report Alternative 1c Construct a Salinity Control Gate at Bayou La Loutre (Normally Closed) Under Alternative 1c, a gated structure would be constructed just downstream of Bayou La Loutre that would allow passage of shallow-draft vessels. The gated structure would have a sill depth of 14 feet and a 125-foot wide opening. The gate would normally be closed to reduce saltwater intrusion, but would be opened for passage of commercial and recreational shallow-draft vessels. This alternative was developed to allow continued shallow-draft navigation and to significantly reduce salinity above the structure. The gate could also close the channel for any tropical storm event and associated storm surge. By keeping the gate closed except when vessels are present, it could have the greatest salinity reduction of all the shallow-draft Alternatives. Removal of deep-draft vessels could significantly reduce bank erosion. Interim Report Alternative 1d Construct a Storm Protection Gate at Bayou La Loutre (Normally Open) This Alternative comprises similar structural components and earthwork as Alternative 1c: a sector gate with tie-in T-wall and earthen dam. This alternative was developed to allow continued shallow-draft navigation, to reduce storm surge from tropical storm events and to reduce salinity above the structure. The gate would be operated to close the channel only for a tropical storm event and associated storm surge. Reduction of salinity could be similar to Alternative 1b above. Removal of deep-draft vessels could significantly reduce bank erosion. Interim Report Alternative 2a Construct an Armored Earthen Dam Across the MRGO at Bayou La Loutre This plan was developed to remove both shallow and deep-draft vessels from the MRGO, reduce salinity and tropical storm surge and allow the most compatibility with a freshwater diversion. It could reduce salinity more than any of the Alternative 1 options. Removal of deep-draft vessels could significantly reduce bank erosion. Interim Report Alternative 2b Restore Both Banks of Bayou La Loutre Across the MRGO at Hopedale, Louisiana Under Alternative 2b, two earthen dams would be constructed to restore the banks of Bayou La Loutre. One dam would connect the ridge on the north side of Bayou La 27

61 Loutre on the Hopedale side with the north ridge on the Biloxi Marsh side. The second dam would connect the south ridges across the MRGO. This would totally block the MRGO channel with two structures. This plan was developed to allow shallow-draft navigation, reduce salinity and tropical storm surge and to totally block access to Bayou La Loutre from the MRGO. Removal of deep-draft vessels could significantly reduce bank erosion. Interim Report Alternative 2c Fill in the Entire MRGO Channel from the GIWW to the Gulf of Mexico Under Alternative 2c, the entire MRGO would be filled from the intersection of the GIWW to Breton Sound. This Alternative has been requested by several stakeholders and was frequently noted in public comments. Recreational craft would not be able to use any portion of the Inland Reach of the MRGO. Interim Report Alternative 3 - Cease All MRGO Operations and Maintenance Activities Under Alternative 3, no additional Federal funds would be used to maintain a minimum channel depth on of the MRGO between the GIWW and the Gulf of Mexico. There would be neither construction nor operation and maintenance costs for this Alternative. This was developed as the least cost plan. It would have no impact on storm surge in tropical storm events or salinity reduction. Removal of deep-draft vessels could significantly reduce bank erosion. 2.3 EVALUATION OF NAVIGATION FUNCTIONS THAT SHOULD BE MAINTAINED The USACE evaluated what navigation functions, if any, should be maintained on the MRGO between the GIWW and the Gulf of Mexico. Analysis of deep-draft navigation indicates that maintaining the authorized dimensions of the MRGO between the GIWW and the Gulf of Mexico is not cost-effective. Average annual operations and maintenance (O&M) costs to dredge a single shipping lane in the MRGO Inland Reach are $12.5 million. However, maintaining a single shipping lane, which is half of the authorized dimensions, only produces approximately $3.7 million per year in transportation efficiencies, based on NED criteria. Efforts to operate and maintain the fully authorized dimensions (i.e. a two-lane channel, 500-feet wide by 36-feet deep) would be even more costly and would not produce greater navigation benefits. The analysis indicates that the maintenance of a deep-draft navigation channel of any dimension on the MRGO between the GIWW and the Gulf of Mexico is not economically justified. The $3.7 million per year in transportation inefficiencies that navigation would incur if the MRGO channel were not available are comprised of two sources. The first source is the increased travel time (approximately 4 hours) that both deep-draft vessels and shallow-draft vessels would have to incur by having to use the Mississippi River to reach their ultimate destinations. The second source is from the shallow-draft traffic that uses the MRGO as an alternate route when the IHNC Lock is not operable. 28

62 Historically, the MRGO has also served as an alternate navigation route for shallow draft vessels during times of extreme congestion at the IHNC Lock or when the lock was inoperable. Before Hurricane Katrina some barge tows would travel downstream on the Mississippi River to Baptiste Collette Bayou, exit Baptiste Collette Bayou into Breton Sound, and then enter the MRGO. Eastbound tows would then travel back inland from Breton Sound on the MRGO to the GIWW Reach before continuing east to locations in Mississippi, Alabama, and Florida (westbound traffic would traverse the opposite route). The alternative route around the IHNC Lock is about 180 miles longer than a direct lock through from the GIWW to the Mississippi River. Vessel operators would weigh factors such as anticipated time of delay, added fuel consumption, weather, and insurance ratings when making a decision to proceed through the alternative route or to wait to pass through the lock. The bypass takes approximately 24 hours to navigate. Approximately 100 vessels use the MRGO as an alternate route per year when the IHNC Lock is not operable. Vessels can save time if the lock is down for a period of greater than 24 hours and/or there is a long queue. The additional time lost from not having access to the MRGO as an alternate route when the IHNC Lock is inoperable has been estimated to be approximately 48 hours. The portion of the $3.7 million per year in transportation inefficiencies that is attributed to the loss of the MRGO as an alternative route when the IHNC Lock is not operable is $400,000 per year. The economic information available also indicates that it is not cost-effective to maintain a shallow-draft channel between the GIWW and the Gulf of Mexico in terms of NED criteria. The benefits of authorizing the MRGO to 12 feet are the reduction in the transportation inefficiencies compared to the total closure option for the channel. If the MRGO were to be closed between the GIWW and the Gulf of Mexico, shallow-draft vessels would have to take a longer alternate route along the Mississippi River. In addition the MRGO would no longer be available as an alternate route to the GIWW for shallow-draft traffic when the IHNC Lock is not functioning or is congested. Taking these two issues into account, it is estimated that the average annual benefits of authorizing the MRGO to 12 feet is $1.2 million (of which $400,000 results from the use of the MRGO as an alternate route when the IHNC Lock is inoperable). The total average annual costs to maintain a 12 foot shallow-draft channel is approximately $6 million. Based on the above analysis, the USACE concluded that no navigation function on the MRGO between the GIWW and the Gulf of Mexico is economically justified. Therefore continued authorization of the MRGO between the GIWW and the Gulf of Mexico for any form of navigation is not economically justified based on the comparison of navigation costs and benefits according to NED criteria. Based on this conclusion, the USACE proceeded to eliminate some alternatives from further study and to carry forward a final array of alternatives for detailed evaluation that would implement de-authorization of the MRGO from the GIWW to the Gulf of Mexico. 29

63 For this report, the USACE used the definition of deep-draft vessels contained in ER (Planning Guidance Notebook), which are those vessels requiring drafts greater than 14 feet. 2.4 ALTERNATIVES ELIMINATED FROM FURTHER STUDY Interim Report Alternatives 1a 1d All of the alternatives identified in the Interim Report to Congress that included maintenance of the MRGO channel for shallow-draft navigation between the GIWW and the Gulf of Mexico were eliminated from further consideration based on economic analysis. Economic information indicates that shallow-draft traffic on the MRGO between the GIWW and the Gulf of Mexico is not cost-effective in terms of National Economic Development (NED) benefits. The total average annual costs to maintain a 12- foot shallow-draft channel between the GIWW and the Gulf of Mexico is approximately $6 million, whereas the estimated annual benefits are approximately $1.2 million. Interim Report Alternative 2b This Alternative was eliminated from further consideration because it achieves similar environmental and navigation results as Alternative 2a, but at approximately twice the cost. Also, when compared with Alternative 2a, there are additional negative impacts to recreational and commercial vessel users because access to Bayou La Loutre from the north is blocked. Interim Report Alternative 2c This Alternative was eliminated from further consideration due to its high cost and the length of time required for full implementation. It is estimated that it would require approximately million cubic yards of dredged material to fill the channel from mile 60 to mile 25 at a cost of about $2.8 billion based on October 2006 price levels. The material could be mined from the ODMDS by a hydraulic dredge, loaded into large scow barges, transported to the Inland Reach and off loaded. Depending on how many scow barges could be employed at once, it could take from 15 to 44 years to completely fill the channel. Other Alternatives Other alternatives were suggested after release of the Interim Report to Congress. These included multiple closure locations, limited channel filling, shoreline restoration and stabilization, and vegetative plantings. Alternatives dealing with ecosystem restoration were deemed to be beyond the authority of the MRGO de-authorization study; however, they will be considered under LACPR and other appropriate authorities. In addition to study authority, alternatives were eliminated from further consideration based upon costs, impacts to the environment, limited availability of construction materials, constructability issues, and effectiveness in meeting the study goals and objectives. Alternatives recommended after release of the Interim Report are discussed in greater detail in Section 4 and in Appendix P. 30

64 2.5 ALTERNATIVES EVALUATED IN DETAIL In order to prepare the Final Report to Congress and the Legislative Environmental Impact Statement, in addition to the Future Without De-authorization three Alternatives were carried into the final array of alternatives for detailed evaluation. The alternatives evaluated in detail are listed below: Future Without De-authorization - The channel would be dredged to the Congressionally authorized dimensions of 500-foot bottom width in the Inland and Sound Reaches and a 600-foot bottom width in the Bar Channel. The channel would be maintained at these widths. Dredged material would be used beneficially behind the jetties and on Breton Island. Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately; Alternative 2 Phased Construction of a Total Closure Structure Across the MRGO Near Bayou La Loutre (phased construction would begin with a weir and be completed with a total closure structure); Alternative 3 Cease All MRGO Operations and Maintenance Dredging Activities Immediately. The following features are common to Alternatives 1, 2, and 3: The MRGO channel would be de-authorized for navigation from mile 60 at the southern bank of the GIWW to the Gulf of Mexico. Aids to navigation and channel markers would be removed at the discretion of the United States Coast Guard. Existing bank stabilization features and jetties would be de-authorized, but left in place Preliminary Engineering on Alternatives Evaluated in Detail Preliminary engineering was conducted on all alternatives carried into the final array for detailed evaluation. The preliminary engineering is presented in Appendix C. The following paragraphs present a summary of the relevant preliminary engineering analyses that influenced plan formulation, particularly pertaining to the location and design of the total closure structure proposed under Alternatives 1 and 2. Determining the location of the proposed total closure structure evaluated in Alternatives 1 and 2 was based on two principle considerations: 1) an appropriate physical location to prevent deep-draft navigation, and 2) engineering and design criteria relevant to site selection for construction. For purposes of preventing deep-draft navigation, closure could occur at many points along the MRGO channel. However, based upon available 31

65 engineering information and design criteria, a site located just south of Bayou La Loutre is most favorable. A number of locations along the MRGO were identified as potential closure structure locations. These included the lower channel at the jetties, and several sites in the vicinity of Bayou La Loutre, Shell Beach, Bayou Dupre, and Bayou Bienvenue. Most of these sites were eliminated because of multiple engineering factors, especially channel width and subsurface soil conditions. The most favorable site for a total closure structure is immediately south of the Bayou La Loutre crossing. This site represents the narrowest section of the channel and offers the best area soil conditions because of proximity to the historic Bayou La Loutre ridge. Based on existing data and historic knowledge of the project site, a preliminary closure design and quantification was prepared to address the closure structure proposed under Alternatives 1 and 2. Designs analyzed included plans for a total channel closure as follows: 1. Dredged-In earthen closure. This approach assumes borrow from the MRGO below the depth of the authorized navigation channel. Assuming that (1) suitable borrow material is found between elevations -50 feet and -70 feet, (2) a 300-foot corridor centered on the MRGO centerline is made available, and (3) a bulking factor of 2.0; an approximate 3 mile reach of borrow corridor would be needed. Due to the potential of less than desirable characterization of the borrow source, this option includes rock toe dikes on both ends of the dike section, perpendicular to the MRGO to assist in retention of materials and to better manage the ultimate side slopes of the closure section. Construction would entail pumping a 300-foot-wide crown structure and maintaining 1V on 30H side slopes. The requirements for consolidation of the dredged material mandate the assumption that at least two construction lifts would be required to complete this effort. Seeding and fertilizing of the resulting berm was included in the cost estimate (see Appendix C). 2. Barged in earthen closure. This option assures a better source of construction materials, and being mechanically placed, allows for steeper side slopes and a smaller crown width. However, the transportation costs associated with barged in material greatly increases cost of the closure structure. Again, only fertilizing and seeding was included in this original estimate; stone paving was assumed for any required repairs. The section was reduced to a 200-foot crown and 1V on 10H side slopes. Consolidation of placed material is a concern, but only one lift was included in this preliminary estimate (see Appendix C). 3. Total Rock Closure. This design assures better control of placed material. It eliminates the concern of consolidation of earthen construction materials. The dimensions of the rock closure assumed 25-foot to 30-foot crown width, with 1V on 2.5H side slopes. This design would result in less maintenance due to reduced structure erosion. Quarry run stone would be specified to increase fines in the mix, minimizing voids and reducing salt water intrusion. Based on assumptions made, this was the least costly design alternative (see Appendix C). 32

66 4. Cellular Sheet Pile Closure. This option consisted of cellular sheet pile structures, sand filled, with stone berm on either side. This design provided a less permeable solution than the total rock closure, but was as much as twice as expensive based on preliminary cost estimates and professional judgment (see Appendix C) Assessment of Planning Risk and Uncertainty Evaluating risk and uncertainty is an important element in realistic forecasting and planning to solve water resources problems. The U.S. Army Corps of Engineers recognizes the need to evaluate risk and uncertainty and has developed several regulatory guidelines for use in project studies and design work. The majority of USACE guidelines for risk assessments are related to flood damage reduction studies (see ER and EM ). However, a primary reference relevant to the MRGO deauthorization study is the Guidelines for Risk and Uncertainty Planning in Water Resources Planning developed through the Institute for Water Resources. An overview of the approach outlined in the document is summarized as: The risk analysis framework involves the well recognized four basic steps in dealing with any risk: characterization, quantification, evaluation, and management. The purpose of conducting these analyses is to provide additional information to Federal and non-federal partner decision makers on the engineering and economic performance of alternative investments that address water resources problems. The aim is to produce better decisions and to foster the development of the notion of informed consent by all parties to an investment decision. The risks involved with planning for the MRGO de-authorization are primarily associated with uncertainties in forecasting future conditions for economic development, navigation utilization, and environmental quality factors. The project delivery team has assessed various data needs and drawn from existing information sources to support project planning. Where feasible the team endeavored to collect new data to characterize conditions in the study area and to aid in system analysis. This information has been quantified in standard metrics for comparison between alternative plans and reporting in the evaluations supporting the recommended plan. Specifically the team identified the rate of channel shoaling and use of the MRGO as an alternative by-pass route as two significant risk and uncertainty factors in the study. Shoaling rates are a critical factor in predicting changes in channel depth and dimensions over time. This information is critical to the assessment of the available use period of the channel as a shallow draft transportation route into the future a key component in the evaluation of alternative 2. The team utilized historic maintenance dredging data collected over the life of the channel to estimate the rate of infilling and the duration that the channel would be available for use by vessels drafting less than 12 feet. According to the data, the sound reach of the channel is estimated to shoal to less than 12 feet in about Uncertainty associated with the estimate centers on the frequency of tropical storms and hurricanes passing through the project area. Storms generate waves and shift bottom sediments resulting in channel shoaling. The team assessment includes 33

67 documenting the assumptions associated with the data and confidence is gained because the data used reflects a full project life period of record keeping. Nonetheless the variability in tropical storm activity raises some uncertainty in the estimate on both the upper and lower ends. Stated more directly a tropical storm or storms could impact the project area in any year rendering the channel inaccessible to shallow draft vessels. The team also noted that the project area might not be impacted by a storm event for a period beyond 2014 resulting in a longer period of shallow draft access. Under certain conditions the MRGO channel is occasionally used as an alternative bypass route around the IHNC Lock. This use is generally limited to periods of heavy congestion, unexpected maintenance closures or scheduled prolonged maintenance work on the IHNC Lock. Information about the frequency of shallow draft utilization under these scenarios is critical to assessing alternatives that would allow for continued shallow draft access on the MRGO. Information on the use of the MRGO in these events was culled from the waterborne commerce statistics. The data was analyzed and usage estimates were developed (including assumptions) and documented in the stakeholder engagements and in the report. The basic assumption is that vessel operators would wait at moorings to pass through the lock rather than opt to use the MRGO-Mississippi River by-pass route as long as the wait time was less than or equal to the added time needed to complete the alternative route. Based upon the trip duration for the by-pass route the trigger period is approximately three days. At the three day point some operators may choose to precede to by-pass the congested or closed lock. The team presented the information to navigation industry trade groups in several venues and the assumption was not challenged. The MRGO project delivery team managed risk by collecting the best available data for use in the study and clearly documenting the assumptions and shortfalls of the information. In addition, the team worked to communicate the data utilized to stakeholders so that interested parties clearly understood the limitations of the analysis. Further parties were offered the opportunity to provide additional data to support the alternatives analysis conducted. The team also worked with Operations Managers for the IHNC Lock to identify maintenance and repair actions that could further minimize the likelihood of prolonged closures of the structure. These actions could be sequenced prior to implementation of the recommended plan in order to bring the lock to the most reliable operations status before the loss of the MRGO as a by-pass route based on funding availability Description of Alternatives Evaluated in Detail Future Without De-authorization The existing MRGO Project completed construction in 1968 at the authorized depth and width. Since construction, the project has been maintained at various depths and widths. For the past few years, the Inland Reach, the Sound Reach and Bar Channel have not been dredged to full dimensions. Rather, the channel has been maintained for one-way traffic only. Due to shoaling the current controlling depth is approximately 22 feet. However, to determine whether it is economically feasible to maintain the project and 34

68 evaluate the environmental impacts for various levels of maintenance including closure, the future without de-authorization is assumed to be a project maintained at the authorized dimensions. The Future Without condition is equivalent to the no-action alternative. All alternatives will be compared to this future condition. When the Inland Reach is dredged to its full, authorized dimensions, all material from the Inland Reach would be placed in upland disposal areas because of difficulties in finding marsh creation sites unencumbered with oyster leases. Based upon previous practices, under the future without project scenario, material from the initial dredging of channel miles 27 to 23 would create approximately 157 acres of wetlands adjacent to and behind the north jetty. Material from the initial dredging of channel miles 23 to 14 would be placed behind the south jetty, creating approximately 1,297 acres of marsh. From channel miles 14 to 3.4, material would be placed at unprotected sites in the sound and it is unlikely that any marsh created would last more than a year because of exposure to open bay waves. Material from the initial dredging of channel miles 3.4 to -4 would be placed on Breton Island to create approximately 215 acres of marsh and barrier island habitat (see Appendix G). Following the restoration of the channel to its full dimensions, it would be maintained at a 500-foot bottom width for the 50-year period of analysis. A 600-foot bottom width would be maintained within the Bar Channel. However, future maintenance operations would depend on funding availability. Material from the Inland Reach would again be placed in upland confined disposal areas. From 1985 to 2004, while maintaining miles 27 to 3.4 to a 500-foot width, an average of approximately 17 acres was created each year behind the jetties. From 1993 to 2005, material between miles 3.4 to -4 was placed either at the feeder berm or just off Breton Island, creating an average of approximately 21 acres per year. It is assumed that these acreages would continue to be created for 50 years in the future without de-authorization (see Appendix G). Approximately 2,702 acres of marsh would be created in 50 years. At the same time 5,045 acres of marsh could be lost due to erosion. Thus, the estimated net loss is 2,343 acres over 50 years (see Appendix G) Alternative 1 Construct a Total Closure Structure across the MRGO Near Bayou La Loutre Immediately This alternative was developed to de-authorize the MRGO channel from Mile 60 at the southern bank of the GIWW to the Gulf of Mexico, by eliminating deep-draft and shallow-draft navigation while protecting the environment from further negative impacts associated with erosion and increased salinity. It achieves positive closure of the MRGO channel, thereby eliminating the possibility of attempted through navigation upon deauthorization. Under this alternative the MRGO channel would be de-authorized for navigation from mile 60 at the southern bank of the GIWW to the Gulf of Mexico. No additional funds would be used to maintain any channel on the MRGO between the GIWW and the Gulf of Mexico. A total closure structure would be constructed just south of Bayou La Loutre 35

69 and would tie in with the southern Bayou La Loutre Ridge to totally block the MRGO channel (see Figure 2.1). The structure would not allow passage of vessels traveling the length of the MRGO. Aids to navigation and channel markers would be removed at the discretion of the United States Coast Guard. Existing bank stabilization features and jetties would be de-authorized, but left in place. The total closure structure would be made of rock and built in one construction effort of 170 days. The structure would be feet wide on the top and its elevation would be + 5 feet MLG. Side slopes of the structure would be 1 V on 2.5 H and the bottom would be feet wide. The estimated total project construction cost of the total closure structure is $17,451,000 based on October 2006 price levels (see Table 2.1). Estimated average OMRR&R cost for the total closure structure is $136,000 per year. Average annual net economic benefits are $7.8 million. Total project costs would be shared as follows: construction costs at 100% Federal; LERRDs at 100% non-federal; and OMRR&R at 100% non-federal. Table 2.1 Alternative 1 Project Construction Costs Alternative 1 Project Construction Costs (October 2006 Price Levels) Alternative 1 Construction Items Cost ($) Mobilization and Demobilization 66,100 Stone Placement - Channel Proper 10,494,000 Stone Placement - Overbank Tie-Ins 243,000 Clearing and Grubbing (Overbank) 16,200 Engineering and Design 743,850 Construction Management 1,082,000 Real Estate 1,401,000 Removal of Aids to Navigation 700,000 Contingencies (25%) 2,704,850 Total Project Construction Costs 17,451, Alternative 2 Phased Construction of a Total Closure Structure Across the MRGO Near Bayou La Loutre (phased construction would begin with a weir and be completed with a total closure structure) This alternative was developed to de-authorize the MRGO channel from Mile 60 at the southern bank of the GIWW to the Gulf of Mexico, as a variation of Alternative 1 that would allow a period of free shallow-draft navigation benefits while ultimately achieving the goal of positive closure of the MRGO channel. The free shallow-draft benefits are derived from a period ending around 2014 during which the channel could accommodate shallow-draft without expenditures on maintenance dredging; however, during this period, the channel would not be Federally authorized, operated, or maintained. Additionally, under this alternative, while erosion and saltwater intrusion are reduced, these impacts continue on a limited basis until the total closure structure is completed. 36

70 Under this alternative, the MRGO channel would be de-authorized for navigation from mile 60 at the southern bank of the GIWW to the Gulf of Mexico. No additional funds would be used to maintain any channel on the MRGO between the GIWW and the Gulf of Mexico. A total closure structure would be constructed just south of Bayou La Loutre using sequenced construction and would tie in with the southern Bayou La Loutre Ridge to totally block the MRGO channel. The total closure structure would be constructed in two phases. Aids to navigation and channel markers would be removed at the discretion of the United States Coast Guard. Existing bank stabilization features and jetties would be de-authorized, but left in place. The first phase would construct a rock closure containing a weir 125-feet wide by 14 feet deep. (Note: The weir would be set at 14 feet depth to allow safe passage of 12-foot draft vessels providing a 2-foot keel/hull clearance over the structure). It is possible that guide walls and dolphin cells would be needed on both sides of the weir to funnel marine traffic through the weir. Design optimization, including possible physical modeling, would be required to assess hydraulic performance and ensure safe navigability through such a structure. The estimated total project construction cost of phase I is $16,608,145 based on October 2006 price levels. Construction of the first phase, the rock weir, would take an estimated 150 days. Once complete, the first phase of construction would allow the passage of vessels with a draft of 12 feet or less. Under this phase, commercial and recreational vessels with a draft less than 12-feet could still use the MRGO until the channel filled in to a depth of 12 feet. The depth of the channel would be monitored. Once any reach filled in to a depth of less than 12 feet, Phase II construction would begin. It is estimated that some reaches of the MRGO would become impassible to vessels with greater than 12-foot draft in approximately The date of 2014 is the best engineering estimate of when any portion of the channel would shoal to a depth less than 12 feet. This shoaling could occur at any time if a tropical storm or hurricane passes over the sound area. If there are no such disturbances, it could be sometime after 2014 that the channel depth would be reduced to 12 feet or less. The second phase of construction would complete the total rock closure by filling the weir opening with rock. The completed structure would not allow passage of any vessels traveling the length of the MRGO. The elevation of the closure would be + 5 feet MLG. The estimated total project construction cost for the second phase is $1,107,485 based on October 2006 price levels. The estimated total project construction cost for Alternative 2 is $17,715,630 (see Table 2.2). Estimated average OMRR&R cost for Alternative 2 is $133,800 per year. The average annual net economic benefits for this phased total closure structure are $8.1 million. Total project costs would be shared as follows: construction costs at 100% Federal; LERRDs at 100% non-federal; and OMRR&R at 100% non-federal. 37

71 Alternative 3 Cease All MRGO Operations and Maintenance Dredging Activities Immediately This alternative was developed to de-authorize the MRGO channel from Mile 60 at the southern bank of the GIWW to the Gulf of Mexico, in the least costly and most expedient manner; however, it does not protect against continued erosion and saltwater intrusion. In addition, it does not achieve positive closure of the MRGO channel, therefore, the possibility of attempted through navigation is not eliminated upon de-authorization under this alternative. Because the channel would remain open, potential issues surrounding vessel damage, insurability, and safety exist; however, because the Federal government is not recommending the continued use of the channel following de-authorization, these potential issues were not quantified. It is anticipated that some vessels will continue to use the channel under this alternative despite deteriorated channel conditions because under current conditions both deep- and shallow-draft vessels utilize the channel which has not been maintained since Hurricane Katrina. For example, the controlling depth of the channel is 22-feet and many aids to navigation were damaged or destroyed by Hurricane Katrina and have not been replaced due to the uncertainty of the future of the channel (see Section ). Discussions with stakeholders in the navigation industry (such as pilots, shipping companies, the Port of New Orleans, dock operators, industry trade groups) and with the USCG indicate that vessels are likely to continue to navigate the MRGO channel until depth conditions become inadequate. This applies to both deepand shallow-draft vessels. After de-authorization, relic aids to navigation would be removed through coordination with the USCG, but navigation is likely to continue under this alternative subject to future channel shoaling. Under this alternative, the MRGO channel would be de-authorized for navigation from mile 60 at the southern bank of the GIWW to the Gulf of Mexico. No additional funds would be used to maintain any channel on the MRGO between the GIWW and the Gulf of Mexico. There would be no construction costs, except 1) aids to navigation and channel markers would be removed at the discretion of the United States Coast Guard and 2) the USACE would dispose of some existing disposal and channel easements. Existing bank stabilization features and jetties would be de-authorized, but left in place. Under this alternative, commercial and recreational shallow-draft vessels could still use the MRGO until the channel filled in to a depth that prohibited their navigation. It is estimated that some reaches of the MRGO would become impassible to vessels greater than 12-foot draft in approximately This year has been used for analyses under this alternative although, a tropical storm or hurricane could cause portions of the channel to shoal much sooner. Total project construction costs are estimated to be $825,000 based on October 2006 price levels (see Table 2.3). Average annual net economic benefits are estimated to be $9.1 million. Total project costs would be shared as follows: construction costs at 100% Federal; LERRDs at 100% non-federal; and OMRR&R at 100% non- Federal. 38

72 Table 2.2 Alternative 2 Project Construction Costs Alternative 2 Project Construction Costs (October 2006 Price Levels) Alternative 1 Construction Items Cost ($) Phase I Mobilization and Demobilization 66,100 Stone Placement 10,143,000 Clearing and Grubbing 16,200 Engineering and Design 702,990 Construction Management 1,022,530 Real Estate 1,401,000 Removal of Aids to Navigation 700,000 Contingencies (25%) 2,556,325 Phase I Subtotal 16,608,145 Mobilization and Demobilization 66,100 Stone Placement 661,320 Engineering and Design 114,555 Construction Management 83,655 Contingencies (25%) 181,855 Phase II Subtotal 1,107,485 Total Project Construction Costs 17,715,630 Figure 2.1 Bayou La Loutre Ridge, site of the Total Closure Structure 39

73 Table 2.3 Alternative 3 Project Construction Costs Alternative 3 Project Construction Costs (October 2006 Price Levels) Alternative 1 Construction Items Cost ($) Real Estate 125,000 Removal of Aids to Navigation 700,000 Total Project Construction Costs 825, COMPARISON OF ALTERNATIVES BASED ON FOUR CRITERIA IN PRINCIPLES AND GUIDELINES In accordance with ER , alternatives evaluated in detail were also evaluated and compared based on the following four criteria: 1) completeness, 2) effectiveness, 3) efficiency, and 4) acceptability, which are described at the beginning of Section 2. The following paragraphs describe the alternatives in terms of these criteria. This comparison is summarized in Table Completeness Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) This plan is not complete. It assumes that the channel would be dredged to its authorized width and depth. However, neither deep-draft nor shallow-draft is economically justified. It requires significant investment to protect the environment and does not account for any other social effects Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately Alternative 1 is the most complete plan because it provides for all the necessary investments to physically close the MRGO to navigation from the GIWW to the Gulf of Mexico as part of de-authorization. Present channel conditions accommodate navigation up to a 22 foot draft. This plan eliminates any possibility of through navigation after deauthorization. The closure structure is not part of a hurricane protection project. The plan reasonably maximizes economic benefits, is the most effective in protecting the environment, and considers other social effects Alternative 2 Phased Construction of a Total Closure Structure Across the MRGO Near Bayou La Loutre Alternative 2 is a slightly less complete plan than Alternative 1 because it is less compatible with LACPR alternatives aimed at the distribution of diverted Mississippi River water throughout the Biloxi Marsh. It eventually provides for all the necessary investments to physically close the MRGO to navigation from the GIWW to the Gulf of Mexico as part of de-authorization. However, it allows shallow-draft navigation until about 2014 without expenditures on maintenance dredging. There will be no navigation 40

74 aids on the de-authorized channel. After about 2014, this alternative eliminates the possibility of through navigation. The phased closure structure is not part of a hurricane protection project. This plan reasonably maximizes economic benefits, is less effective in protecting the environment up to 2014, and is not fully responsive to other social effects Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately Alternative 3 is not a complete plan. It provides none of the necessary investments to physically close the MRGO to navigation from the GIWW to the Gulf of Mexico. The plan allows possibility of through navigation after de-authorization. There will be no navigation aids on the de-authorized channel. Present channel conditions accommodate navigation up to a 22 foot draft. Vessels may attempt to navigate the channel after it is de-authorized. This plan provides the maximum economic benefits, but does not address environmental or social effects Effectiveness Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) This is the least effective alternative because it does not de-authorize deep-draft navigation on the MRGO channel from the GIWW to the Gulf of Mexico as directed by Public Law Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately This alternative is effective because it de-authorizes deep-draft navigation on the MRGO channel from the GIWW to the Gulf of Mexico as directed by Public Law Alternative 2 Phased Construction of a Total Closure Structure Across the MRGO Near Bayou La Loutre This alternative is effective because it de-authorizes deep-draft navigation on the MRGO channel from the GIWW to the Gulf of Mexico as directed by Public Law Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately This alternative is effective because it de-authorizes deep-draft navigation on the MRGO channel from the GIWW to the Gulf of Mexico as directed by Public Law Efficiency Cost and benefit information used to evaluate the efficiency of each alternative is displayed in Table Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) The future without de-authorization is the least efficient alternative. It is estimated that this plan produces a net economic loss to the nation. With the average annual cost to maintain the authorized channel to be approximately $12.5 million and the average 41

75 annual benefit to navigation (both deep-draft and shallow-draft traffic) to be approximately $3.7 million, plus the cost to return the channel to authorized dimensions of $130 million, the corresponding B/C ratio is 0.17 to 1. The annual maintenance cost used in this assessment is based upon appropriations received in the past. As noted earlier, since about 1998 this funding level has only been adequate for the maintenance of a one-way channel not the fully authorized dimensions of the MRGO. Maintenance dredging to provide the full authorized dimensions would require higher levels of annual O&M funding. More significantly, a major dredging event to restore the post-katrina channel to authorized dimensions has been estimated to exceed $130 million. In addition, future annual O&M costs do not reflect the periodic need for emergency supplemental funds required for dredging after tropical storms and hurricanes Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately This plan will produce a net economic benefit, however when compared to alternative 2 and alternative 3, it produces the fewest average annual net economic benefits ($7.8 million) and the smallest B/C ratio of 2.6 to 1, because of the cost of constructing the closure structure and the loss of all navigation benefits once the closure structure is installed Alternative 2 Phased Construction of a Total Closure Structure Across the MRGO Near Bayou La Loutre When compared to alternative 1, this plan will produce a slightly better net economic benefit. This is due to the fact that shallow draft traffic may still be able to use the channel for a period of time (until the channel is closed due to shoaling in about 2014) once the channel is de-authorized and construction of a full closure structure can be delayed. However, when compared to alternative 3, it is less efficient because of the cost of constructing a closure structure. The average annual net economic benefit for this alternative is estimated to be $8.1 million producing a B/C ratio of 2.8 to 1. Uncertainties regarding the rate of future channel shoaling greatly effect the confidence in this B/C ratio Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately When compared to alternative 1 and 2, this plan produces the highest average annual net economic benefit ($9.1 million) and the highest B/C ratio (3.7 to 1). This is due to the fact that shallow draft traffic may still be able to use the channel for a period of time (until the channel is closed due to shoaling in about 2014, as is the case with alternative 2), and because it requires minimal investment. Uncertainties regarding the rate of future channel shoaling greatly effect the confidence in this B/C ratio Acceptability ER discusses acceptability as the workability and viability of the alternative plan with respect to acceptance by Federal and non-federal entities and the public and compatibility with existing laws, regulations, and public policies. Two primary dimensions on acceptability are implementability and satisfaction. 42

76 1) Implementability means that the alternative is feasible from technical, environmental, economic, financial, political, legal, institutional, and social perspectives. If an alternative is not feasible due to any of these factors, then it can not be implemented, and therefore is not acceptable. An infeasible plan should not be carried forward for further consideration. 2) The second dimension to acceptability is the satisfaction that a particular plan brings to government entities and the public. The extent to which a plan is welcome or satisfactory is a qualitative judgment. Discussions as to the degree of support (or lack thereof) enjoyed by particular alternatives from a community, state Department of Natural Resources, Ducks Unlimited, or other national or regional organizations, for example, are additional pieces of information that can help planners evaluate whether to carry forward or screen out alternative plans. Table 2.4 Average Annual Benefits and Costs by Alternative Average Annual Benefits and Costs by Alternative (October 2006 Price Level, 50-Year Period of Analysis, Percent Discount Rate) Future Without De-authorization Alternative 1 Alternative 2 Alternative 3 Cost ($) Cost ($) Cost ($) Cost ($) Investment Costs Total Project Construction Costs 130,445,000 17,451,000 17,715, ,000 Interest During Construction 6,360, , ,000 18,700 Total Investment Cost 136,805,000 17,758,000 18,005, ,700 Average Annual Costs Interest and Amortization of Initial Investment 6,682, , ,900 42,300 Deep-Draft Transportation Cost 2,500,000 2,500,000 2,500,000 Shallow-Draft Transportation Cost 1,200, , ,400 OMRR&R 12,500, , ,800 Total Average Annual Costs 19,182,000 4,730,200 4,399,200 3,413,700 Average Annual Benefits 3,700,000 $12,500,000 $12,500,000 $12,500,000 Net Annual Benefits -15,482,000 $7,769,800 $8,100,800 $9,086,300 Benefit-Cost Ratio 0.19 to to to to 1 Benefit-Cost Ratio (computed at 7%)* 0.17 to to to to 1 *Per Executive Order Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) Maintaining the MRGO to the authorized depth and width would clearly fail the test of implementability. An overview and comparison of the final alternatives against the four P&G criteria is provided in Table 2.5. The Future Without De-authorization is not acceptable because it is not feasible in terms of economic, financial, political, or social factors. In addition, it has the highest 43

77 environmental impacts. This plan is least compatible with comprehensive ecosystem restoration strategies It does not restore the Bayou La Loutre Ridge which was a hydrologic barrier and a natural line of storm defense. The ridge protected marshes to north from rapid tidal exchanges. The ridge may remain open for 50 years. This plan would not reduce salinity in the Pontchartrain Basin north of Bayou La Loutre. Salinity might remain steady in the Middle Basin and could increase in the Lower Basin (Tate et al. 2002). With the future without de-authorization, beneficial use of dredged material would create 2,702 acres of marsh behind the jetties and on Breton Island. However, shoreline erosion would destroy 4,565 acres of marsh for a net loss of 2,343 acres of marsh. It is unlikely that sea turtles would be found in the Inland Reach. Turtles would continue to be taken in the Bar Channel during maintenance dredging and ship impacts.. The size and cost of any potential freshwater diversion projects would be the highest of any alternative. There would be greater marsh loss on the MRGO/Lake Borgne Landbridge and thus more resources would be required to protect and restore this landbridge. This scenario is also not acceptable to the State of Louisiana, area parish governments, adjacent landowners or several local and national environmental Non- Governmental Organizations. This alternative is not included in the local government, state government, and environmental organization plans for coastal Louisiana. For the above mentioned reasons, it is unacceptable and should not be implemented Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately Alternative 1 is the most politically feasible plan. The Louisiana Congressional delegation and local politicians strongly support a total closure. This plan is less economically feasible than alternative 3, but it has many other positive attributes. Alternative 1 is the most socially feasible plan. Citizens of St. Bernard, Orleans, Jefferson and St. Tammany Parishes, all affected by Katrina, generally believe that the MRGO is a hurricane highway, despite strong scientific data that demonstrates otherwise. Thus, the general citizenry of southeastern Louisiana is highly supportive of a positive closure. Numerous comments on the LEIS also favored at least one closure in the MRGO. Alternative 1 is the most satisfactory to the State of Louisiana. The State of Louisiana has taken a number of significant actions related to the future of the MRGO and clearly identified its position on the de-authorization of the channel. Key pieces of information highlighting the state's position include: 1. A letter from the Governor calling for immediate closure of the MRGO. In a June 2006 letter Governor Blanco wrote General Riley regarding the MRGO stating "I write to unequivocally express the policy of this State regarding the future of the Mississippi River Gulf Outlet (MRGO) my Advisory Commission on Coastal Protection, Restoration and Conservation has recommended the immediate closure of this channel." (see Appendix A). 2. The completion of a Master Plan for Coastal Protection and Restoration highlighting total closure of the MRGO. The State Master Plan calls for the 44

78 immediate closure of the MRGO. To quote, Immediately construct a closure dam at Bayou LaLoutre The Master Plan was developed with intensive public input and was unanimously adopted by the Louisiana Legislature. 3. Passage of state appropriations in the current fiscal year dedicated to cosponsoring MRGO closure. The Fiscal Year 08 State Annual Plan includes funds for the LERRDs associated with the proposed total closure structure. 4. Provision of a letter of interest in serving as the non-federal sponsor. The State of Louisiana has expressed an understanding of the current law and administration policy regarding implementation of Federal water resources projects. In a letter of intent dated September 25, 2007, the Chair of the Coastal Protection and Restoration Authority of Louisiana (CPRA) expressed the State of Louisiana s interest in sharing the costs of implementing the recommendations of this report... dependent upon the nature of the local cooperation requirements and their specific costs (see Appendix O). 5. Self-certification of the non-federal sponsor's financial capability. The state certified its financial capability to serve as the local cost share sponsor for the MRGO closure plan. (see Attachment 1). 6. Participation in the project Civil Works Review Board and expression of strong commitment and support for the recommended plan. 7. The State of Louisiana has committed to provide a revised letter of assurance that clearly articulates their desire to serve as the non-federal sponsor. A letter meeting this requirement is anticipated from the state in November The closure is also highly satisfactory to local citizens and citizens of other parts of the country as evidenced by public meeting comments and comments on the Draft Report/LEIS. Many non-governmental organizations (local and national) find the closure highly satisfactory when compared to the other alternatives. Alternative 1 appears to be highly satisfactory to adjacent landowners when compared to the other alternatives. Alternative 1 is highly unsatisfactory to navigation interests because they lose deep-draft access to infrastructure on the IHNC and the GIWW until the IHNC Lock is replaced. They have also expressed desire for an alternative route around the IHNC Lock. The team has recognized these comments and worked diligently to seek resolution. However, in the end, no reasonable alternatives were identified to satisfy concerns regarding the low probability of impacts to the shallow draft industry. No cost effective shallow draft alternatives are likely to exist based on the low level of benefits and the rare occurrence of using the MRGO as a by-pass around the IHNC Lock. Thus, it can be concluded that Alternative 1 is clearly the most acceptable plan for MRGO de-authorization based on both feasibility and satisfaction. 45

79 Construction of a rock closure structure at Bayou La Loutre is the most acceptable plan across a range of additional goals and objectives. These include de-authorizing the Federal navigation channel, the highest level of environmental benefits, and compatibility with LACPR alternatives. This plan would immediately restore the portion of ridge cut by MRGO. Restoration could allow wildlife to cross the ridge and return tidal flow to pre-mrgo conditions. This plan is likely to immediately reduce salinity north of the closure structure. The MRGO/Lake Borgne Landbridge could change from the saline marsh it is now to a brackish marsh type. More intermediate marsh and cypress could occur in Central Wetlands. Once in place, the closure structure might quickly reduce size of H/A Zone in Lake Pontchartrain. These could then also reduce H-A Zone. The plan is estimated to prevent the potential loss of a significant percent of the 2,343 net acres of marsh estimated to be lost under the future without de-authorization. The closure structure would remove deep-draft navigation and could allow sea turtles to reoccupy Inland Reach Alternative 2 Phased Construction of a Total Closure Structure Across the MRGO Near Bayou La Loutre Alternative 2 is less politically feasible than Alternative 1 the Louisiana political delegation and local politicians favor an immediate closure. Alternative 2 is more economically feasible than Alternative 1. It is less socially feasible than Alternative 1 because citizens have expressed a desire for immediate closure. Alternative 2 is less satisfactory than Alternative 1 to the State of Louisiana, local parishes, adjacent landowners and various NGOs. Alternative 2 is slightly more satisfactory to navigation interests than alternative 1 because it allows shallow-draft navigation until about In conclusion, Alternative 2 is less feasible and satisfactory than Alternative 1. This plan is not advisable by the USCG, and it is unacceptable to the shallow-draft navigation industry because of uncertainties surrounding future channel shoaling. This alternative is not consistent with the State of Louisiana's Master Plan for Coastal Protection and Restoration and it does not satisfy the expressed goals and interests of local governments and several local and national environmental Non-Governmental Organizations. This alternative is not included in the local governments, state government, and environmental organization plans for coastal Louisiana. This alternative is less acceptable than Alternative 1 for additional reasons. The Bayou La Loutre Ridge would not be restored until about There would be no ridge restoration benefits during this period, then benefits for a ridge would be the same as Alternative 1. This plan would provide some immediate salinity reduction north of the notched structure, but not as much as Alternative 1. The return of marsh to a less saline habitat type on the MRGO/Lake Borgne Landbridge and in the Central Wetlands is unlikely to occur until about Then when the closure structure is completed, Alternative 2 would have same benefits as Alternative 1. Benefits of reducing the H/A Zone in Lake Pontchartrain would be same as those for Alternative 1. There would be slightly less marsh loss prevented than with Alternative 1 due to possibility of shallowdraft navigation until about The phased closure structure would remove deep-draft navigation and could allow sea turtles to reoccupy Inland Reach. This alternative would be less compatible than Alternative 1 until about 2014 in relation to ecosystem 46

80 restoration, the freshwater diversion at Violet would have to be larger and restoration of the landbridge would be more costly Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately Alternative 3 may maximize economic benefits better than Alternative 1, but as indicated above, it clearly fails the test of implementability from political and social perspectives. Thus, it is unacceptable and should not be implemented. This plan is not advisable by the USCG, and it is unacceptable to the shallow-draft navigation industry because of uncertainties surrounding future channel shoaling. Table 2.5 provides an overview and comparison of alternatives against each of the four P&G criteria. This alternative is not acceptable because it is not feasible in terms of political or social considerations. This alternative has higher environmental impacts to area wetlands and estuarine salinity than Alternatives 1&2. This plan does not meet the expressed goals of local government, landowners, or environmental NGOs. In addition, the alternative is not consistent with the State of Louisiana's Master Plan for Coastal Protection and Restoration. The state has indicated that this alternative (along with the Future Without De-authorization and Alternative 2) is deemed inconsistent with the Louisiana Coastal Zone Management Plan as approved by the National Oceanic and Atmospheric Administration (U.S. Department of Commerce). This alternative is not included in the local governments, state government, and environmental organization plans for coastal Louisiana. This plan is less acceptable than Alternative 1 or 2 for additional reasons. Under this alternative the Bayou La Loutre Ridge would never be restored and would remain open for the 50 year period of analysis and beyond. There would be essentially no salinity reduction for many years. Salinity might increase in Lower Basin as per Tate et al. Marsh types would probably remain as at present and not become less saline. Changes in H-A Zone are unlikely until USACE constructs measures to reduce storm surge into IHNC. It is possible that deep-draft vessels might use the channel longer than with Alternative 2. Thus, there could be a higher percentage of the estimated 2,343-acre marsh loss than Alternative 2. Once deep-draft vessels ceased to use the de-authorized channel, sea turtles could reoccupy Inland Reach. This Alternative would be less compatible for comprehensive ecosystem restoration than Alternative 2 but more compatible than the future without de-authorization. Cost of a potential Violet Canal freshwater diversion and restoration of the landbridge would fall between Alternative 2 and the future without de-authorization. 2.7 ALTERNATIVE 2 ELIMINATED FROM FURTHER EVALUATION Alternative 2 was eliminated from further evaluation based on the comparison of alternatives based on the four criteria in principles and guidelines presented in Section 2.6 and the assessment of planning risk and uncertainty presented in Section Therefore, Alternative 2 was not carried forward for the evaluation and comparison of environmental consequences presented in Section 3. 47

81 Alternative 2 was eliminated from further evaluation because it was deemed to be less complete, effective, and acceptable than Alternative 1 and less efficient than Alternative 3. Additionally, the benefits that may be derived from shallow-draft navigation usage before 2014 under Alternative 2 are speculative in nature because of the planning risk and uncertainty surrounding the potential rate of future MRGO channel shoaling. Given the risk and uncertainty and the performance of the alternative when evaluated against the four criteria in principles and guidelines, Alternative 2 was eliminated from further evaluation. 48

82 Table 2.5 Comparison of Alternatives Based on Four Criteria in Principles and Guidelines CRITERIA FUTURE WITHOUT DE- AUTHORIZATION ALTERNATIVE 1 ALTERNATIVE 2 ALTERNATIVE 3 Completeness Not a complete plan. It does not meet the study objective of deauthorizing the channel. Assumes channel is dredged to authorized dimensions (recognizing appropriations limits). However, neither deepdraft nor shallow-draft is economically justified. Most complete plan; it provides positive closure of de-authorized channel immediately. Plan eliminates possibility of through navigation after deauthorization. Second most complete plan; it de-authorizes the channel but allows shallow-draft navigation until about 2014, when closure structure is completed. Marginally complete plan; it de-authorizes the channel but does not physically close the deauthorized channel. Plan allows possibility of through navigation after de-authorization 7. Will be no navigation aids on de-authorized channel. Effectiveness Efficiency Least effective because does not de-authorize the channel. Most costly and least benefits. B/C is 0.17 to 1 Effective at meeting the requirement of deauthorizing the project. Third most costly. B/C is 2.5 to 1 Effective at meeting the requirement of deauthorizing the project. Second most costly. B/C is 2.7 to 1 Effective at meeting the requirement of deauthorizing the project. Least Costly. B/C is 3.7 to 1 Acceptability Not acceptable (see details below). Most acceptable (see details below). Partially acceptable (see details below) Technically feasible Yes Yes Yes Yes Environmental Not environmentally Highly environmentally Less environmentally Acceptability acceptable acceptable acceptable than Alt. 1 Not acceptable (see details below). Not environmentally acceptable 49

83 Salinity reduction Salinity in the Pontchartrain Basin would remain changed from historic conditions (Salinity should stay stable in Mid-Basin and might increase in Lower Basin as land loss from various causes continues). (see Section 3 and Appendix D). Habitat types are expected to generally remain as they are at present. Marsh loss Beneficial use could create 2,702 acres of marsh; erosion would likely destroy 4,565 acres of marsh for a net loss over 50 years that could be of 2,343 acres. (see Section 3 and Slightly reduced salinity is expected throughout the project area soon after completion of closure structure (modeling indicates greatest reduction could be at Alluvial City ppt; salinity stratification north of the structure would be reduced; it is expected that the size of the H-A zone in Lake Pontchartrain could shrink). (see Section 3 and Appendix D). MRGO/Lake Borgne Landbridge could return to brackish marsh. More intermediate marsh and cypress could occur in Central Wetlands. Marsh loss could be decreased by a significant percentage of the 2,343 acre net loss of the future without. (see Section 3 and Appendix G). Fewer salinity improvements prior to completion of closure structure in about (see Section 3 and Appendix D). Marsh change on Landbridge and in Central Wetlands unlikely to occur until about Then when closure completed, Alt. 2 would have same benefits as Alt. 1. H-A Zone same as Alt. 1. Slightly less marsh loss prevented than under Alt.1 because shallowdraft navigation could use the channel until about (see Section 3 and Appendix G). Salinity is unlikely to become lower for several years until much of the channel shoals. (see Section 3 and Appendix D). Salinity might increase in Lower Basin. Marsh types should remain as at present. Change in H-A Zone unlikely until USACE constructs measures to reduce storm surge into IHNC. More marsh loss than Alternative 1, but probably significantly less than future without. (see Section 3 and Appendix G). 50

84 Endangered species (sea turtles) Restores Bayou La Loutre Ridge Appendix G). Unlikely that sea turtles would be found in Inland Reach. Turtles would continue be taken in the Bar Channel. Ridge was a hydrologic barrier and a natural Line of Defense that protected marshes to north. Ridge may remain open for 50 years. Could allow sea turtles to reoccupy Inland Reach. 1 Immediately restores ridge function cut by MRGO. Restoration could allow wildlife to cross the MRGO, reduce salinity (see below) and return tidal flow to pre-mrgo conditions. Could allow sea turtles to reoccupy Inland Reach. 1 Ridge function not fully restored until about No restoration benefits during that period, then same as Alt. 1. Sea turtles could reoccupy Inland Reach once deep/large shallow-draft vessels ceased using channel Ridge function never restored, MRGO would remain an open connection from the Gulf to Lake Borgne for 50 years. Economically feasible No Yes, see efficiency Yes, see efficiency Yes, see efficiency Financially feasible No Yes Yes Yes Politically feasible No Yes, highly Less politically feasible No 5 than Alt. 1. Compatibility with non- Federal plans for Coastal Louisiana Compatibility with USACE initiatives (LACPR, LCA, This alternative is not included in the local government, state government, and environmental organization plans for coastal Louisiana mentioned under Alt. 1. Least compatible with comprehensive ecosystem restoration. The channel closure is included in a number of local government, state government, and environmental organization plans for coastal Louisiana (see Section ). Most compatible with comprehensive ecosystem restoration. This alternative is not included in the local government, state government, and environmental organization plans for coastal Louisiana mentioned under Alt. 1. This alternative would be less compatible than Alternative 1 until about This alternative is not included in the local government, state government, and environmental organization plans for coastal Louisiana mentioned under Alt. 1. Less compatible for comprehensive ecosystem restoration 51

85 CWPPRA Restoration Plan) Specifically, the size and cost of any potential freshwater diversion projects would be the highest of any alternative and there would be greater marsh loss on the MRGO/Lake Borgne Landbridge and thus more resources would be required to protect and restore this landbridge. Satisfactory to State Highly unsatisfactory and inconsistent with State Master Plan. Specifically, consistent and supportive of many previous assessments of MRGO environmental solutions including the Louisiana Coastal Area Ecosystem Restoration Plan, CWPPRA Restoration Plan, and the elements under consideration for the LACPR study; the size and cost of a freshwater diversion at the Violet Canal could be the smallest compared to other alternatives; and restoration of the MRGO/Lake Borgne Landbridge would be the least costly. Highly satisfactory and consistent with the State Master Plan in relation to ecosystem restoration. Specifically, a freshwater diversion at Violet Canal would have to be larger and restoration of the landbridge would be more costly. Marginally satisfactory and inconsistent with State Master Plan until than Alt. 2 but more compatible than future without deauthorization. Cost of potential Violet Canal freshwater diversion and restoration of the landbridge would fall between Alternative 2 and the future without de-authorization. Highly unsatisfactory and inconsistent with State Master Plan. Legally feasible Yes Yes Yes Yes Institutionally feasible Yes Yes Yes Yes Socially feasible 6 No Yes, highly Yes, but less feasible No 5 than Alt. 1. Satisfactory to local parishes 2 Highly unsatisfactory Highly satisfactory compared to other Less satisfactory than Alt. 1. Highly unsatisfactory 52

86 Satisfactory to adjacent landowners Satisfactory to various non-governmental organizations s 3 Satisfactory to navigation interests 4 Highly unsatisfactory Highly unsatisfactory Satisfies some interests in the industry that expressed support for restoring coastal Louisiana while maintaining shallow draft alternative route. alternatives and future without. Highly satisfactory compared to other alternatives and future without. Highly satisfactory compared to other alternatives and future without. Highly unsatisfactory because feasible shallow draft alternate route not available. Less satisfactory than Alt. 1. Less satisfactory than Alt. 1. Unsatisfactory because feasible shallow draft alternate route only available until Does not satisfy expressed concerns. Highly unsatisfactory Unsatisfactory because alternate route not available after about National Marine Fisheries Service letter dated September 14, St. Bernard, Orleans, Jefferson, St. Tammany 3 Coalition to Restore Coastal Louisiana, Lake Pontchartrain Basin Foundation, Environmental Defense, National Audubon Society, National Wildlife Federation, Louisiana Wildlife Federation, American Rivers, Gulf Restoration Network, levees.org 4 Port of New Orleans, Shell, CITGO, Soluta, U.S. Coast Guard, Rhodia, Lonestar, Gulf States Maritime, Gulf Intracoastal Canal Assn., American Waterway Operators, Kirby Corp, Ed Peterson 5 Implementability means that the alternative is feasible from technical, environmental, economic, financial, political, legal, institutional, and social perspectives. If it is not feasible due to any of these factors, then it can not be implemented, and therefore is not acceptable. However, just because a plan is not the preferred plan of a non-federal sponsor does not make it infeasible or unacceptable ipso facto (ER E3. a(4)(a)(1). 6 Information on social feasibility was gathered from a number of public meetings and feedback from stakeholders (see Section 4). 7 Discussions with stakeholders in the navigation industry (such as pilots, shipping companies, the Port of New Orleans, dock operators, industry trade groups) and with the USCG indicate that vessels are likely to continue to navigate the MRGO channel until depth conditions become inadequate for ocean vessel transits. Shallow draft vessels are also likely to continue to use the channel as long as adequate depth remains for their navigation purposes. Many aids to navigation were damaged or destroyed by hurricane Katrina and have not been replaced due to the uncertainty of the future of the channel. After de-authorization, relic aids to navigation would be removed through coordination with the USCG, but navigation is likely to continue unless the channel is physically blocked. 53

87 2.8 EVALUATION AND COMPARISON OF REMAINING ALTERNATIVES The Future Without De-authorization, Alternative 1 and Alternative 3 were analyzed in Section 3 using comparable information to assess relative consequences to the environment. The impact of each alternative across a range of significant resources is presented in Table The following text compares the Future Without De- Authorization, Alternative 1, and Alternative 3 relative to this assessment of environmental impacts. A comparison of total project construction costs and average annual benefits and costs for each alternative are presented in Table 2.4. Under the Future Without De-authorization, it is anticipated that navigation use would return to pre-katrina levels; however, it has been determined that this level of navigation use does not economically justify a continued Federal interest in the authorized Project. The Future Without De-authorization also results in net environmental losses. Approximately 2,702 acres of marsh could be created by beneficial use in 50 years, but, about 5,045 acres of marsh could be lost to wake and wave erosion. Thus there could be an estimated net loss of about 2,343 acres of marsh during the 50 year period of analysis. There would be no salinity reduction in the Pontchartrain Basin under the Future Without De-authorization and habitat types would remain as they are today. The "H-A Zone" in Lake Pontchartrain would continue to occur nearly every year. The Future Without Deauthorization has little compatibility with other potential ecosystem restoration efforts, such as a freshwater diversion structure at Violet. Alternative 1 provides a physical closure to eliminate attempted navigation on the channel after de-authorization and maximizes protection of the environment. In addition, compatible with the study authority (Section 1.2), Alternative 1 has the highest compatibility with other potential ecosystem restoration efforts being considered under LACPR, such as a freshwater diversion structure at Violet. Alternative 1 immediately closes the MRGO to all navigation, thereby eliminating potential through navigation which could occur prior to the channel shoaling in naturally. It yields the fewest average annual net economic benefits ($7.8 million) because all navigation benefits are lost as soon as the total closure structure is installed. Shallow-draft tows that use the MRGO as an alternate route when the IHNC is congested or unexpectedly closed could no longer do so. (Note: this cost is included in calculation of net economic benefits). There is the potential for erosion to increase along the banks of Bayou La Loutre and other waterways if vessels currently using the MRGO channel utilize the other waterways as alternative routes; however, although this is not quantifiable the positive impacts of the alternative far outweigh any impacts to alternative routes. Alternative 1 could prevent a significant percentage of the 2,343 net acres of marsh estimated to be lost over 50 years under the future without condition. Greater salinity reduction and vegetation change to historic habitat types is anticipated to occur over a larger area. It is estimated that there could be a reduction in the size of the H-A zone in Lake Pontchartrain. If authorized and funded, Alternative 1 could be built in one construction effort lasting an estimated 170 days. Alternative 2 was eliminated from further evaluation. 54

88 Alternative 3 maximizes net economic benefits; however, it fails to reduce the negative environmental impacts associated with erosion and increased salinity since it does not provide a physical closure of the channel and therefore through navigation of the channel would be limited only by natural shoaling. Additionally, Alternative 3 is not as compatible with the ecosystem restoration goals of LACPR as Alternative 1. Alternative 3 yields the greatest average annual net economic benefits ($9.1 million) because it requires minimal investment and because shallow-draft navigation benefits would only be limited by natural shoaling within the channel. Alternative 3 has no construction costs, except 1) aids to navigation and channel markers would be removed at the discretion of the United States Coast Guard and 2) the USACE would dispose of some existing disposal and channel easements. This alternative could be implemented almost immediately after Congressional authorization and appropriation. Shallow-draft navigation would be prohibited over time because the channel would not be maintained; however shallow-draft navigation would not be impeded by a structure. Most shallowdraft navigation would be unable to use the Sound Reach of the channel after about Shallow-draft tows that use the MRGO as an alternative route when the IHNC is congested or unexpectedly closed could no longer do so after about 2014 (Note: this cost is included in the calculation of net economic benefits). It is estimated that slightly more marsh would be lost than under Alternative 1, but significantly less than under the future without condition. It is estimated that Alternative 3 is unlikely to influence salinity or marsh vegetation types or reduce the H-A zone in Lake Pontchartrain. Additionally, potential future ecosystem restoration measures, such as a freshwater diversion structure at Violet, could be more difficult to implement than under Alternative 1. For example, without a structure in the MRGO channel, a much larger freshwater diversion would be required at Violet, which would increase cost significantly and decrease the ability to control desired environmental results within the greater Pontchartrain Basin. Assessment of this alternative also raised questions about whether or not the alternative could be classified as comprehensive and therefore responsive to the Congressional direction. 2.9 RATIONALE FOR SELECTING RECOMMENDED PLAN Alternative 1 has been selected as the Recommended Plan. The Recommended Plan is consistent with the study authority as described in Public Law and explained in House Report (see Section 1.2). The Recommended Plan also fulfills the study purpose and need (see Section 1.5) and the study goals and objectives (see Section 1.6) which are derived from the study authority. The Recommended Plan presents a comprehensive plan to de-authorize all navigation on the MRGO channel from the GIWW to the Gulf of Mexico; proposes that navigation function be maintained outside of the GIWW to Gulf of Mexico portion of the channel; proposes plan features; and proposes existing project features to be de-authorized or to remain authorized (see Section 6.1). The Recommended Plan minimized cost associated with the disposition of the de-authorized project while meeting the criteria of completeness, effectiveness, efficiency and acceptability. The Recommended Plan results in $7.8 million in net annual benefits, reduces negative environmental impacts in the study area through reductions in erosion and salinity, and may reduce the size of the H-A zone in Lake Pontchartrain. The Recommended Plan was developed in consultation with St. Bernard Parish, the State of Louisiana, and affected Federal Agencies, as well as other stakeholders and the general 55

89 public (see Section 4). While the Recommended Plan does not propose hurricane or storm damage reduction features, the Recommended Plan was identified because it is more compatible with the goals of LACPR than Alternative 3. The Recommended Plan is acceptable, complete and effective as evaluated under the P&G criteria. Although the plan is not the least cost alternative, it is recommended because it fully meets three of the four P&G criteria while Alternative 3, the least cost alternative, only fulfills the efficiency criteria. Additionally, the Recommended Plan is consistent with all of the alternatives being evaluated under LACPR and can be fully integrated into any of the LACPR plans under consideration. The Recommended Plan provides for reduced salinities in areas targeted for restoration under LACPR, LCA, CWPPRA, as well as, restoration efforts of other Federal and State agencies. Reduction in salinities will improve the effectiveness of, and likely reduce the cost of, ecosystem restoration measures planned for these areas. The MRGO Final Report and LEIS will be included in the LACPR Final Report. Specific features of the Recommended Plan are addressed in Section 6. 56

90 SECTION 3 AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES This section first generally describes the project area. The remainder of the chapter presents conditions for each significant resource, future without de-authorization conditions and then the direct and indirect impacts of the two alternatives on these significant resources. Significant resources presented include: water quality (with an emphasis on salinity); vegetation; wildlife; fisheries; essential fish habitat; threatened and endangered species; recreation; cultural resources; aesthetics; air quality; navigation; business; employment and community cohesion. Comparative and cumulative impacts of the alternatives are analyzed at the end of the chapter. 3.1 PROJECT AREA DESCRIPTION Land Characteristics The project area is located in southeastern Louisiana in St. Bernard, Orleans, Jefferson, St. Charles, St. John the Baptist, Tangipahoa and St. Tammany Parishes (see Figure 1.1). It covers the Lower Pontchartrain Basin, which consists of Lake Borgne, the MRGO, a portion of the Gulf of Mexico, Chandeleur and Breton Sounds, surrounding wetlands, and small towns near the Mississippi River. The Middle Pontchartrain Basin is also in the project area. It consists of Lake Pontchartrain with its adjacent cities and towns and surrounding wetlands. New Orleans and Metairie lie on the south bank of the lake. The remainder of the lakeshore is mainly wetlands. The MRGO channel, located southeast and east of New Orleans, is in the Lower Pontchartrain Basin. The channel begins in the Gulf of Mexico and extends through the shallow waters of Breton Sound. There are three- and eight-mile long rock jetties extending from the mainland into the sound on the north and south sides of the channel. Then for 37 miles, the MRGO passes through coastal wetlands. About 10 miles inland, the channel cuts through a relic distributary of the Mississippi River, Bayou La Loutre, and its natural ridge. Bayou La Loutre continues westward from the MRGO to Bayou Terre aux Boeufs and meanders eastward of the MRGO through the Biloxi Marshes. A 4,000-foot wide disposal area built with dredged material from the MRGO lies immediately southwest of the MRGO channel. The marshes of Breton Sound lie directly west of the southern portion of the disposal area. Although there is a small hydrologic connection, the MRGO has very little influence in the Breton Sound wetlands. About 10 miles up the MRGO from Bayou La Loutre, there is a hurricane protection levee constructed on a portion of the disposal area adjacent to the MRGO channel. There are shoreline protection features all along this portion of the disposal area. The levee runs atop the disposal area northwestward along the MRGO to the GIWW. A local levee, known as the Forty Arpent Levee, is found immediately west of the Central Wetlands. Open water and wetlands exist northeast of the MRGO. North of Bayou La Loutre, Lake Borgne lies northeast of the channel. There is a landbridge of marsh and ponds between MRGO and the lake, the landbridge is very narrow in two places. The larger towns of St. Bernard Parish (Chalmette, Mereax, Violet, and Poydras) are found between the Forty 57

91 Arpent Levee and the Mississippi River. Some small fishing towns lie outside the hurricane protection levee, such as Yscloskey, Shell Beach, and Hopedale. The MRGO connects with the GIWW at the northwest end of the Inland Reach at which point the MRGO and the GIWW run contiguously westward for 6 miles to the IHNC (also called the Industrial Canal) in New Orleans. Hurricane protection levees are located on portions of the north and south disposal areas of the GIWW Reach. The IHNC runs between the Mississippi River and Lake Pontchartrain. The nearly 90-year old IHNC Lock lies at the southern end of the IHNC and provides access to the Mississippi River. The city of New Orleans lies on either side of the IHNC Climate The project area has a subtropical marine climate strongly influenced by the water surface of many sounds, bays, lakes and the Gulf of Mexico. Prevailing southerly winds increase the marine climate characteristics. During the fall and winter, the project area experiences cold continental air masses which produce frontal passages with temperature drops. During the spring and summer, the project area experiences tropical air masses which produce a warm, moist airflow conducive to thunderstorm development. The project area is susceptible to tropical storms and hurricanes. These weather systems can cause considerable property and environmental damage and loss of human life. The most recent hurricanes were Katrina and Rita in 2005, which caused devastating damage in the project area. 3.2 SIGNIFICANT RESOURCES Water Quality Over the past 6,000 to 7,000 years, salinity in the project area has shifted with the major deltaic meandering of the Mississippi River. Modern efforts to control flooding and improve navigation included numerous bank stabilization, channel alignment, dredging, lock, dam, levee, and spillway projects on the Mississippi River. Such alterations to the Mississippi River and surrounding wetlands have increased salinity in the project area by altering the flow of freshwater in the region (USACE 2004). Prior to construction of the MRGO typical tidal flow within the Breton Sound area was reduced as it moved across the marshes and wetlands inward toward Lake Borgne (USACE 2004). The Bayou La Loutre ridge provided a basin boundary that limited the flow of saline water from the Breton Sound area into Lake Borgne (Rounsefell 1964). The MRGO provides a more direct flow of higher salinity and higher density water inland toward areas of St. Bernard and Orleans Parishes due to the breaching of the La Loutre Ridge (Wicker, et al. 1981). A hypoxic/anoxic zone in Lake Pontchartrain was first described by Poirrier (1978). Its existence was verified by extensive water quality sampling done by DEQ in 1980 and 1982 (Schurtz and St. Pe, 1984). This zone appears to be caused primarily because the MRGO carries bottom water in excess of 20 parts per thousand (ppt) which enters the 58

92 IHNC and then Lake Pontchartrain during the flood tide cycle (Georgiou and McCorquodale 2002). This saline water sinks to the bottom where it moves with the bottom lake currents and can cover at least 1/6 of the lake s bottom. This stratified water inhibits both mixing and oxygenation, generally leading to hypoxic (low oxygen) or anoxic (no oxygen) conditions near the lake bottom (Schurtz and St. Pe 1984). This H-A zone seems to appear most often in the spring and summer (Abadie and Poirrier 2001). Coliform levels along the MRGO have usually exceeded the DEQ criteria, indicating a widespread area of water and wetlands that are subject to bacterial pollution. The likely source is nearby populated areas. Measured dissolved oxygen levels at Bayou Dupre have consistently been above the minimum state standard and Environmental Protection Agency (EPA) criteria. With rare exceptions, the ph measurements also have been within the desirable range of 6.5 to 9.0. Toxic substances, including heavy metals and synthetic organics, have been measured above EPA criteria levels, but no patterns consistently exceeding the criteria for particular substances have been observed Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) No significant increase in average annual salinity is projected in the foreseeable future for Lake Maurepas and Lake Pontchartrain. Salinity is expected to increase in the Lake Borgne region and surrounding marshes due to wetland loss in the area (Tate, et al. 2002; USACE 2004). Other water quality parameters would likely remain unchanged. The H- A zone in Lake Pontchartrain could continue to exist Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately During construction of the total closure structure, turbidity would be temporarily increased and dissolved oxygen could drop in the vicinity of the work. In 2002, researchers modeled the seasonal changes in salinity that might occur in the Lake Pontchartrain Basin as a result of varying the depth and width of the MRGO at the Bayou La Loutre ridge (Tate, et al. 2002). Results of the study are presented in Appendix D. The biggest modeled reductions in salinity are at Martello Castle and Alluvial City north of the closure and adjacent to the MRGO (see Figure 1.1). By lowering salinity stratification north of the total closure structure, it is possible that much of the stratification in Lake Pontchartrain could be reduced. and it is expected that the size of the H-A zone in the lake could shrink (Abadie and Poirrier 2001). Other water quality parameters in MRGO and vicinity might remain unchanged Alternative 3 - Cease All MRGO Operations and Maintenance Activities Immediately It is estimated that salinity could remain as it is for several years. In about 2014, the Breton Sound segment of the MRGO could silt to 12 feet. The channel across the sound would eventually reach ambient depth. USACE estimates the jetty reach might not silt to 12 feet for 15 years and the lower half of the Inland Reach could take 40 years to reach 12 feet. It is estimated that salinity might gradually drop as channel depth decreases, but 59

93 tides and southerly winds could continue to push water with high salinity up the MRGO for many years Vegetation Coastal Louisiana was created by the Mississippi River as it moved across the landscape over the last 7,000 years. It would create a delta, then find a shorter way to the Gulf and create another delta as the former one deteriorated. Bayous Sauvage and La Loutre were Mississippi River distributaries that created much of Orleans and St. Bernard Parishes. When Europeans arrived, they started taming the river with levees so the area could be inhabited. After the 1927 flood, the river was leveed most of its way through Louisiana. These levees prevented the nearly annual flooding that brought sediment and nutrients to the wetlands and sustained them. Channels were dug for navigation and canals to extract petroleum which changed the hydrology of the wetlands, allowed saltwater to move into freshwater wetlands and ponded water on other wetlands (USACE 2004). Nutria were introduced in the 1930 s and escaped and now damage wetlands. Natural subsidence is occurring at a rate of approximately one to three feet per century in the study area (USACE 2004). Storms also cause erosion and hurricanes can destroy significant amounts of marsh. For these natural and man-made reasons, coastal Louisiana is losing about 24 square miles of wetlands per year (Barras et al. 2003). Table 3.1 shows habitat change and wetland loss between 1956 and 1990 in the project area, which amounts to a loss of 68,660 acres of wetlands. Factors such as subsidence, navigation channels, oil and gas exploration and production, development and storms have contributed to these losses. Approximately 67 percent of the swamp in the project area was lost while saline marsh gained 8 percent. Table 3.1 Habitat Change in Project Area Middle and Lower Basin Wetlands Fresh/intermediate Marsh 24,780 22,270 21,280 Brackish Marsh 145, , ,360 Saline Marsh 74,020 60,220 79,645 Swamp 43,620 20,760 14,600 Total 287, , ,950 (Wicker, 1980; Barras, Bourgeois, Handley, 1994) Habitat mapping was done by O Neil in 1949, Chabreck, Joanen and Palmisano in 1968, and Chabreck and Linscombe in 1978, 1988 and The description below is based on these maps (USGS 2002). Marsh type is dependent on salinity which is generally determined by rainfall and maninduced changes such as channel and canal dredging. The exact locations and acreages of fresh and intermediate marshes in the project area have fluctuated over time, probably depending on rainfall during the year. Intermediate marsh has been present in the Central Wetlands three of the five years it has been mapped. Brackish marsh has decreased significantly in acreage and fluctuated slightly in location throughout the habitat type mapping period. From saline marsh was only found south of the Bayou La 60

94 Loutre ridge and in the outer Biloxi Marshes. In 1988 saline marsh had encroached up the MRGO to about Bayou Dupre and into the Biloxi Marshes near the MRGO. By 1997, it was found further north along the MRGO, past Bayou Dupre Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) Following the restoration of the channel to its full dimensions, which is expected to create about 1,512 acres of marsh, it would be maintained for the 50-year period of analysis. There would be no beneficial use in the Inland Reach because material would be placed in upland confined disposal areas. Based on past dredging volumes, an average of approximately 17 acres is estimated to be created each year behind the jetties. An average of approximately 21 aces per year is assumed to be created on Breton Island. Numerous factors contribute to wetlands losses and coastal erosion in the project area including delta deterioration, subsidence, canal and channel construction, wind and wake erosion, salt water intrusion, oil and gas exploration, herbivory, and storms. In order to estimate how many of these created wetlands would remain in 50 years, a standard Wetland Value Assessment spread sheet was used (Roy, 2006). Taking into account the acres assumed created each year and subtracting the acres estimated to be lost each year, there would be approximately 2,702 acres remaining at the end of the fifty year period of analysis. However, during the same 50 years, erosion along unprotected areas of the MRGO north bank would result in the loss of approximately 4,565 acres of marsh. There could be an estimated net loss of about 2,343 acres of marsh over the 50-year period of analysis (see Appendix G) Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately There would be no beneficial use of dredged material. It is assumed that there would be less bank erosion on the MRGO between the GIWW and the Gulf of Mexico than with the future without condition since there would be no deep- or shallow-draft traffic on the closed channel. It is possible that the loss prevented might be a significant percent of the 2,343 net loss of the future without condition. Although data are not available to permit quantifying changes in vegetation, it is unlikely that the changes in salinities due to closure could cause any large-scale changes in vegetation types within the Pontchartrain Basin. Two areas immediately adjacent to the MRGO may experience changes in habitat type. Modeling results (Tate et al., 2002) indicate that a total closure structure would return salinity to the brackish marsh salinity range of 4-15 ppt at all months between Martello Castle and Bayou La Loutre (see Appendix D, Exhibit 2). Thus, the land bridge east of MRGO should become brackish marsh most years. In the Central Wetlands, there could be intermediate marsh near the Forty Arpent Levee and more cypress should regenerate. 61

95 Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately It can be assumed that some deep and shallow-draft vessels could use the channel until about 2014, which is estimated to cause more bank erosion on unprotected banks of the MRGO than Alternative 1. Compared to the future without de-authorization, this alternative is anticipated to cause significantly less future marsh loss because deep and shallow-draft vessels will be unable to use the channel for over 40 years. Salinity in the basin is not likely to change significantly and therefore marsh types would probably remain as at present Wildlife Kerlin (1979) described the wetlands of St. Bernard Parish, south of Lake Borgne, as being second only to the marshes of the lower Mississippi River Delta in importance to waterfowl in southeastern Louisiana. The area supported at least 250,000 ducks during the winter and was important for the production of muskrat, nutria, mink, river otter, and raccoon, all staples of the Louisiana fur industry. Since about 1970, waterfowl and furbearers have declined in the lower basin (Kerlin 1979). However, they are still present. Alligators too have declined, but are still present (Kinler and Campbell 2002). Birds found in the project area include nine species of wading birds, more than five species of seabirds, four species of shorebirds, six species of songbirds, and several raptor species. Game mammals present are swamp rabbit, raccoon, and fox/gray squirrels. Non-game mammals include opossum, nine-banded armadillo, and several species of bats, rodents, and insectivores (USFWS 1997). Personnel from Louisiana Department of Wildlife and Fisheries, U.S. Fish and Wildlife Service and Natural Resources Conservation Service provided recent (since 1985) trends in wildlife for the 1998 Coast 2050 Study (Louisiana Coastal Wetlands Conservation and Restoration Task Force and the Wetlands Conservation and Restoration Authority.1998). They assessed common wildlife in the mapping units of the Middle and Lower Basin. Populations of seabirds, shorebirds, dabbling and diving ducks and raptors have been generally steady there since Around Lake Pontchartrain populations of furbearers, game mammals and alligators have been steady. In the lower basin, these animals have generally been decreasing since The bald eagle was officially removed from the List of Endangered and Threatened Species as of August 8, However, it continues to be protected under the Migratory Bird Treaty Act (MBTA) and the Bald and Golden Eagle Protection Act (BGEPA). The USFWS developed the National Bald Eagle Management (NBEM) Guidelines to provide landowners, land managers, and others with information and recommendations regarding how to minimize potential project impacts to bald eagles, particularly where such impacts may constitute disturbance, which is prohibited by the BGEPA. Those guidelines recommend maintaining: (1) a specified distance between the activity and the nest (buffer area); (2) natural areas (preferably forested) between the activity and nest trees (landscape buffers); and (3) avoiding certain activities during the breeding season. The buffer areas serve to minimize visual and auditory impacts associated with human 62

96 activities near nest sites. Ideally, buffers would be large enough to protect existing nest trees and provide for alternative or replacement nest trees. On-site personnel should be informed of the possible presence of nesting bald eagles within the project boundary, and should identify, avoid, and immediately report any such nests to the USFWS Regional Office located in Lafayette, Louisiana. A copy of the NBEM Guidelines is available at: delines.pdf. Bald eagles are currently winter breeding residents in southern Louisiana. Section 10 of the Main Report provides common and scientific names of plants and animals mentioned throughout this report and appendices Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) Marsh loss that is estimated to occur with this scenario means that there could be less habitat available for wildlife that utilizes marshes such as waterfowl and furbearers. It is possible that this could lead to fewer numbers of certain species, such as mallards, greenwinged teal and muskrat. Although bald eagles are unlikely to nest near the MRGO channel, they may use the area as forage. However, they are likely to avoid the area during maintenance dredging and temporarily disperse into adjacent areas with available foraging habitat Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately The estimated reduction in marsh loss could increase the abundance of wildlife that utilizes marsh, such as wading birds and sea birds, compared to the future without deauthorization. The reduction of salinity above the total closure structure could improve portions of the project area slightly for waterfowl and furbearers. Although bald eagles are unlikely to nest near the proposed project area, they may use the area as forage. However, they are likely to avoid the project site during construction and disperse into adjacent areas with available foraging habitat Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately It is possible that there could be less of an increase of marsh-dependent wildlife than Alternative 1. Salinity in the basin is not likely to change significantly, so habitat for waterfowl and furbearers are anticipated to stay as it is now. Bald eagles are unlikely to be affected under this alternative Fisheries Rounsefell (1964) characterized fishery resources in the marsh and bayou areas now traversed by the MRGO using bimonthly sampling data collected by the Texas Agricultural and Mechanical Research Foundation during the period July 1959 to March 1961 (El-Sayed 1961). Estuarine-marine species dominated the fish communities with spot, Atlantic croaker, anchovy, and sea trout ranked among the top 10 species in every area sampled. Only two freshwater species, blue catfish and sunfish, ranked among the top 10 species. Four non-migratory estuarine species ranked among the top 10 species in 63

97 each of the lower salinity areas. Four marine species were among the top 10 most abundant species in the higher salinity areas (El-Sayed 1961). The five most widespread and economically important fish species (spot, Atlantic croaker, anchovy, sea trout, and Gulf menhaden) were more abundant in the higher salinity areas. Neither brown shrimp nor white shrimp exhibited notable salinity preferences and were transient residents of the marshes. Small blue crabs were most abundant in low salinity waters (Rounsefell 1964). Fontenot and Rogillio (1970) sampled Lake Borgne and the Biloxi Marshes from They reported an overall increase in salinity in the early 1960 s. Of the 22 species of freshwater fish caught early in the study, 10 species disappeared by the end of the study. Ecological affinities were evenly distributed with 32 percent freshwater species, 29 percent estuarine-marine species, and 29 percent marine species. The six important sport fish in the area, spotted sea trout, Atlantic croaker, black drum, red drum, spot and Gulf sheepshead, were not influenced by the increased salinity. Lake Pontchartrain was studied by Thompson and Fitzhugh (1985) who described it as having a strong freshwater species component before MRGO with freshwater fish comprising 33 percent of the species, marine fishes 30 percent and estuarine-marine species 20 percent. However, estuarine-marine species dominated the lake in numbers of individuals with Atlantic croaker, Gulf menhaden, sand seatrout and red drum being common. White shrimp were more common than brown shrimp most years. Much of the lake bottom was disturbed by dredging for Rangia clams. Large clams were generally found only near the edges of the lake (Thompson and Fitzhugh 1985). While studying Lake Pontchartrain, Thompson and Fitzhugh (1985) found that the 10 most abundant species showed patterns of relative abundance similar to pre-mrgo surveys. Bay anchovy and Atlantic croaker were the most abundant in all studies. However, species diversity declined dramatically after MRGO. In the 1950s otter trawls yielded species; in the 1970s, only species were collected. White shrimp landings generally decreased, while brown shrimp landings increased after the construction of MRGO in both Lake Pontchartrain and Lake Borgne, most likely as a result of salinity increases (Thompson and Fitzhugh 1985). Benthic species were taken less frequently in 1978 than in , indicating deterioration of the lake bottom due to shell dredging (Sikora and Sikora 1982). Shell dredging ceased in 1990 and the benthos was expected to improve (Abadie and Poirrier 2000). Personnel from Louisiana Department of Wildlife and Fisheries and National Marine Fisheries Service provided recent (last years) trends in fisheries for the 1998 Coast 2050 Study (Louisiana Coastal Wetlands Conservation and Restoration Task Force and the Wetlands Conservation and Restoration Authority.1998). They assessed common commercial and recreational fish in the mapping units of the Middle and Lower Basin. They found trends had been steady for red and black drum, brown land white shrimp, 64

98 spotted seatrout, blue crab, American oyster, Gulf menhaden and southern flounder in most of the area. Red drum have been increasing in the Biloxi Marshes and Eloi Bay. The oyster has been decreasing in the Central Wetlands and Eloi Bay. The H-A zone which appears to develop primarily due to high salinity from the MRGO adversely affects benthos. In the spring and summer, there are often no large Rangia clams in the 1/6 of the lake often affected by the H-A zone. Other sessile benthic organisms are probably adversely impacted during the hypoxic events (Junot et al. 1983) Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) During dredging, turbidity would temporarily increase. Fish could avoid the turbid area. Benthos would be destroyed by actual dredging and by disposal in the sound. However, populations should return in a few months. Some shallow-water benthos would be destroyed during marsh creation, but it could be replaced with the benthos typical of a saline marsh. It is probable that the six most important sport fish could be present in at least the same numbers as they are now. In Lake Pontchartrain large Rangia clams and other benthos are expected to remain absent from the H-A zone. Fishery production in the lake could remain as it is at present. In the Lower Basin a net loss of marsh might cause a slight decline in estuarine dependent fish. Fishery distribution in the Upper Basin should remain as it is at present because salinity has stabilized (Tate et al. 2002) Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately Placement of the total closure structure could destroy about 17 acres of benthic habitat. Reducing marsh loss is estimated to improve estuarine dependent fisheries compared to the future without de-authorization. Passage for fish up and down MRGO would be blocked by the total closure structure. There are numerous alternate routes such as Bayou La Loutre, the Back Levee Canal, Lena Lagoon, Lake Athanasio, Alabama Bayou, and others that would allow organism movements through the estuary. Portions of the basin north of the total closure structure could become slightly less saline (see Water Quality). Rock surfaces of the total structure could be utilized as an attachment surface by epiphytic algae and invertebrates that form an additional food web base. Fishery abundance and distribution should increase slightly compared to the future without. It is probable that the six most important sport fish could be present in at least the same numbers as they are now. Salinity stratification in Lake Pontchartrain could be reduced and the H-A zone is estimated to be diminished. This could allow large Rangia clams to exist throughout the lake and other sessile benthos could increase, which should provide more food for fish that rely on benthos Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately Salinity in the basin is not likely to change significantly. There are expected to be slightly less improvements in estuarine-dependent fisheries than Alternative 1. It is 65

99 probable that the six most important sport fish might be present in the same numbers as they are now. In Lake Pontchartrain, large Rangia clams and other benthos are expected to remain absent from the H-A zone. Thus fisheries in the lake could remain as they are today Essential Fish Habitat (EFH) The Magnuson-Stevens Fishery Conservation and Management Act, mandating protection of Essential Fish Habitat, became law in Essential fish habitats are those waters and substrate necessary to fish for spawning, breeding, feeding or growth to maturity. Specific categories of EFH include all estuarine waters and substrates (mud, sand, shell, rock, and associated biological communities), including the sub-tidal vegetation (sea grasses and algae) and adjacent inter-tidal vegetation (marshes and mangroves). The Gulf of Mexico Fishery Management Plan (FMP) designates the fresh, estuarine, and marine waters in St. Bernard Parish as EFH. The FMP manages several fisheries occurring in St. Bernard Parish or adjoining waters; they include brown shrimp, white shrimp, red drum, gray snapper, and Spanish mackerel. Categories of EFH in St. Bernard Parish have been designated by the Gulf of Mexico Fishery Management Council through the 1998 generic amendment of the FMP for the Gulf of Mexico. In the Inland Reach of the MRGO white shrimp, brown shrimp, red drum, and sharks are likely to be present. EFH in the project area includes the estuarine waters and substrates of the MRGO channel cut and adjacent water bottoms from the Gulf of Mexico to Mile 60. Substrates include mud bottoms, some of which have been dredged and re-deposited Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) Bottom habitat would be temporarily disturbed during dredging and open water disposal in the sound. Marsh could be created with dredged material in amounts as were created pre-katrina and bank erosion on the unprotected portions of the north bank could continue. There could possibly be a net loss of marsh over 50 years, all valuable EFH Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately There could be destruction of about 17 acres of EFH on the bottom of the MRGO at the total closure structure location. Passage for brown and white shrimp, sharks and red drum up and down MRGO would be blocked by the total closure structure. However, there are numerous alternate routes such as Bayou La Loutre, the Back Levee Canal, Lena Lagoon, Lake Athanasio, Alabama Bayou, and others that would allow for continued organism movement through the estuary. Compared to the future without deauthorization, it is possible that this alternative could decrease future marsh loss increasing valuable EFH. 66

100 Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately There would be no dredging so EFH at the bottom of MRGO and in disposal areas in the sound would not be temporarily disturbed. The channel would slowly shoal, when filled significantly it would be more valuable EFH. Compared to the future without deauthorization, this alternative is expected to significantly decrease future marsh EFH loss, but the decrease is not likely to be as much as that in Alternative Threatened and Endangered Species The Endangered Species Act of 1973 protects Federally listed species and their designated critical habitats. A variety of whales including several threatened and endangered species ply the deeper waters of the Gulf of Mexico, but would not normally be expected to occur in inshore or near shore waters. The hawksbill sea turtle (E) and leatherback sea turtle (E) are extremely rare in this portion of the Gulf of Mexico, and only occasional strays occur in Louisiana Prior to Hurricane Katrina, the USACE used dredged material from Breton Sound to create an average of 21 acres of barrier island habitat per year on Breton Island. No placement of dredged material has occurred on Breton Island since Hurricane Katrina. Hurricane Katrina nearly destroyed all of South Breton Island and left only a small piece of North Breton. The remainder of the Chandeleur chain was also severely damaged. In the past, brown pelicans bred on Breton Island and foraged in the waters of Breton and Chandeleur Sounds. Brown pelican nesting success has apparently decreased since Hurricane Ivan in However, brown pelicans are not presently nesting, and have not nested in the recent past on Breton Island. In the early 2000 s, brown pelicans nested on islands created by the USACE at Baptiste Collette Bayou. These islands do not appear heavily damaged by the 2005 hurricane season. Prior to the hurricane seasons, wintering piping plovers occasionally used exposed flats in the area, especially on the Chandeleur Islands, including Breton Island. Portions of these islands are designated as Critical Habitats. The loggerhead sea-turtle occasionally occurs in the MRGO in the vicinity of the Bar Channel. Kemp s Ridley sea turtle has appeared recently in some numbers in the Grand Isle/Grand Terre area, and apparently occurs in the vicinity of the MRGO. The green sea turtle has also been sighted in the vicinity of the MRGO. Sea turtles are apparently rare in the MRGO. When dredging occurs, sea turtle generally leave the vicinity of the dredge. Manatees have been sighted within the MRGO, and are known to travel long distances up coastal waterways from the Gulf of Mexico. On July 9, 2001, a manatee was observed passing safely through the IHNC Lock and into the Mississippi River. Manatees are usually within Louisiana coastal waterways only during the warm weather/warm water months. 67

101 Reports of incidental catches and sightings show that the Gulf sturgeon exists within several coastal waterways and lakes in southeast Louisiana, including those connected to the MRGO. Lake Pontchartrain east of the Causeway and Lake Borgne are designated as Critical Habitat for the Gulf sturgeon. The potential exists for Gulf sturgeon to be within the MRGO through access from Breton Sound, Lake Borgne, the IHNC, and the GIWW. In 2006, USACE, MVN prepared an extensive draft Biological Assessment to address impacts that USACE navigational operations and maintenance projects might have on the Gulf sturgeon. Data and conclusions from this report are incorporated by reference into this LEIS. The Gulf sturgeon spends the late fall, winter and early spring foraging in the Gulf of Mexico and its estuaries such as Lakes Borgne and Pontchartrain. They then enter coastal rivers like the Pearl River April through June to spawn and rest. The sturgeon leave the rivers for the estuaries and the Gulf September through November. There have been four records of Gulf sturgeon within the project area. In 1974 a commercial fisherman reported taking a 7-foot Gulf sturgeon in Bayou Bienvenue. A commercial fisherman in 1983 reported catching a 6-foot Gulf sturgeon in Violet Canal. In 1990, Louisiana Wildlife and Fisheries (LDWF) personnel captured a 32-inch Gulf sturgeon in Lena s Lagoon near the MRGO. In January 2005 a sturgeon was found in the MRGO near the Breton Sound Marina during an USACE study of sonic-tagged Gulf sturgeon (Kirk 2007). Estuaries near river mouths are important because adults and sub-adults have fasted while in the river. They eat available polychaetes, gastropods, isopods and amphipods. They prefer sandy bottoms such as those found in Lake Pontchartrain near Goose Point, Fountainbleau State Park, and just west of Hwy 11. The eastern part of the lake is an important wintering habitat for sub-adults and juveniles Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) Beneficial use of dredged material could continue on Breton Island and this area could be available for use by brown pelicans and wintering piping plovers. Existing detailed dredging contract conservation specifications dealing with manatees, Gulf sturgeon, and sea turtles would continue, as would coordination with USFWS and National Marine Fisheries Service (NMFS). Sea turtles, in agreed upon numbers would continue to be taken in the Bar Channel. Thus, the maintenance of the deep-draft channel is not likely to adversely affect threatened or endangered species Alternative 1 - Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately Any brown pelicans that might occur in the project area during construction and maintenance could be temporarily displaced to nearby suitable habitat. There could be less habitat for brown pelicans and less Critical Habitat for the piping plover since there would be no beneficial use on Breton Island because maintenance dredging would cease. No more sea turtles would be taken in the Bar Channel. For construction of the total 68

102 closure structure, existing detailed contract specifications which protect sea turtles, manatees and Gulf sturgeon would continue, as would coordination with USFWS and NMFS (see Appendix J). Passage for Gulf sturgeon and manatees up and down MRGO would be blocked by the total closure structure. However, there are numerous other alternate routes such as Bayou La Loutre, the Back Levee Canal, Lena Lagoon, Lake Athanasio, Alabama Bayou, and others that allow for fish passage through this portion of the estuary. Thus, construction and maintenance of the total closure structure is not likely to adversely affect threatened or endangered species Alternative 3- Cease All MRGO Operations and Maintenance Dredging Activities Immediately There would be no impacts to endangered or threatened sea turtles since the Bar Channel would not be dredged. There could be less habitat for brown pelicans and less Critical Habitat for the piping plover since there would be no beneficial use of dredged material on Breton Island. This alternative is not likely to adversely affect any endangered or threatened species Natural and Scenic Rivers System The Louisiana Natural and Scenic Rivers System was established in There are presently seven waterways designated by the State of Louisiana as Natural and Scenic Rivers in the vicinity of the MRGO (see Figure 3.1). The portion of Bayou Bienvenue from Bayou Villere to Lake Borgne is designated. The remaining designated waterways in the project area are in the Central Wetlands with Pirogue, Bashman and Terre Beau Bayous being clustered around the area where Bayou Dupre (also scenic) goes through the MRGO disposal area. Bayou Chaperon is about 2 miles north of Bayou Dupre and runs from the Forty Arpent Levee northeastward to the MRGO disposal area. The Lake Borgne Canal (Violet Canal) runs from the Mississippi River levee to the Central Wetlands where it meets Bayou Dupre Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) Maintaining the authorized deep-draft channel should have essentially no impact on any Louisiana natural and scenic rivers Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately Construction of the total closure structure should have essentially no impact on any Louisiana natural and scenic rivers Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately No impact. 69

103 Figure 3.1 Natural and Scenic Rivers System 70

104 3.2.8 Air Quality Congress passed The Clean Air Act in 1963 during construction of MRGO. St. Bernard Parish is currently classified in attainment of all NAAQS (USEPA EA #PO-30). This classification is the result of area-wide air quality modeling studies Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) This alternative would have no impact on present air quality and attainment status. However, ambient air quality would be impacted temporarily due to the emissions of dredges in the project vicinity. At construction cessation, air quality in the project area would return to pre-construction conditions. The total volatile organic compound emissions for this project during construction are anticipated to be well below the minimum level of 100 tons/year. Therefore, this action conforms to the Louisiana State Implementation Plan Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately Impacts would be the same as future without described above Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately No impacts Recreation Resources Several non-corps, state and Federal areas within or adjacent to the project area, provide recreational resources to the public (see Table 3.2). Many of the Important Birding Areas (IBA) in Louisiana recognized by the National Audubon Society (NAS) are State or Federally operated areas. In this basin the NAS lists Breton National Wildlife Refuge (NWR) as an IBA. According to an April 2007 press release by the NAS, The Breton/Chandler barrier island chain once housed tens of thousands of nesting terns and ducks, more than enough to meet the criteria as a global IBA for congregatory species. Despite the loss of 50% of their habitat area as a result of Hurricane Katrina, these islands still support globally important populations of Royal and Sandwich terns. Marsh losses in the area are associated with the channel and other factors such as subsidence, storms, development and oil and gas exploration. However, habitat loss apparently has not influenced the six important sport fish in the area, spotted sea trout, Atlantic croaker, black drum, red drum, spot and Gulf sheepshead. Overall, there are less freshwater fish caught in the area today compared to historic data. Species diversity has declined, reducing the variety of fish caught by recreational fisherman (Thompson and Fitzhugh 1985). Waterfowl hunting in the area has changed due to elimination of valuable wintering habitat according to biologists of the LDWF. The marshes south of Lake Borgne are of less value to certain types of waterfowl (snow geese, mallard, and green-winged teal) due to salinity intrusion and marsh deterioration caused by many factors. Recreational 71

105 hunting for certain species has been adversely affected locally but remains strong in other areas of the state. Access to fishing and hunting areas is through bayous, canals and by way of the MRGO via boat launch ramps. Table 3.2 Major Public Recreation Resources within Lake Pontchartrain Basin State of Louisiana US Fish and Wildlife Service National Wildlife Refuges (NWR) Lake Pontchartrain Sanctuary Bayou Sauvage NWR Trawling is prohibited in Lake Maurepas and that portion of Lake Pontchartrain from the shoreline 1 ¼ miles out from the Jefferson Orleans Parish line west to South Point, from South Point along the railroad bridge west from the railroad bridge to Goose Point. Trawling is prohibited between the railroad bridge and the I-10 in Lake Pontchartrain. A refuge of 22,770 acres with estimated annual visitation of 400,000 with a value of $15 million; one of its objectives is to provide opportunities for fish and wildlife-oriented recreation in an urban setting, offering trails, fishing, bird watching, canoeing, photography, bicycle path, crawfishing and crabbing, van tours and wildlife observations. Breton NWR A refuge of 18,000 acres, of which 5,000 acres are designated as Class 1 Wilderness, with estimated annual visitation of 100,000 with a value of $10 million. Public opportunities include fishing, photography, camping and bird watching. Big Branch NWR A refuge of 15,000 acres offering environmental education, birding, fishing, hunting, biking, hiking and canoeing. Louisiana Wildlife and Fisheries (LDWF) Wildlife Management Areas (WMA) Biloxi WMA Joyce WMA Manchac WMA Pearl River WMA St. Tammany Wildlife Refuge 39,583 acres, offering hunting and fishing, camping, boating, crabbing, shrimping and bird watching. 15,609 acres offering hunting, fishing crawfishing, bird watching and berry picking. 8,325 acres, offering hunting, fishing, crabbing with a drop net and bird watching. 34,896 acres, offering fishing, canoeing, boating, crawfishing, waterfowl hunting, and camping. 1, acres remain managed as a wildlife refuge. A variety of resident wildlife species inhabit the refuge including furbearers and alligators. It also serves as a resting and feeding area for wintering waterfowl Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) Recreation fishing would be temporarily disturbed during dredging operations. Much of the recreational activities occurring in Louisiana consist of hunting, fishing and wildlife viewing. Each of these activities are directly related to the conditions of natural resources of the area, and affected by land loss and changes in habitat diversity, and wildlife and fisheries populations that are expected to occur under the future without deauthorization. Populations of migratory birds and other animals could decrease that are directly dependent on the marsh and swamp. Recreational resources in the project area that would be most affected in the future without action are those related to possible loss of wetlands/marshes and habitat diversity. Many recreational activities are based on aquatic resources and directly related to the habitat and species in an area. Habitat changes affect the wildlife populations, thereby affecting many recreational resources. Because salinity levels are expected to be 72

106 stable in the Middle Basin over the future without-project condition, little habitat change is expected. Habitat change could occur in the Lower Basin. However, loss of marshland from various causes over the project life and an increase in open water might have slight impacts on recreational fishing and hunting for estuarine-dependent species over the project life. Fishery habitats might decline as spawning places in the marsh are destroyed. A slight decline in the game population would also affect the hunting opportunities. Access to fishing and hunting areas would be through bayous, canals and by way of the MRGO via boat launch ramps Alternative 1: Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately The MRGO would no longer be used for access to points south of Bayou La Loutre. Passage for fish up and down the MRGO would be blocked by the total closure structure. However, many other local waterways are available as an alternative. Because fishery abundance and distribution are expected to increase slightly as compared to the future without de-authorization, there could be minimal but positive impacts on recreational fishing and hunting. The six most important sport fish could be present in the same numbers as they are now. Estuarine-dependent fisheries could also be positively impacted due to decreased loss in marsh habitat compared to future without deauthorization conditions. Lower salinity in portions of the project area is anticipated to have minimal positive effects on waterfowl compared to the future without deauthorization Alternative 3: Cease All MRGO Operations and Maintenance Dredging Activities Immediately Under this condition, the MRGO between the GIWW and the Gulf of Mexico would not be dredged so recreational resources would temporarily be undisturbed. The channel would slowly shoal over time. Wetlands loss is anticipated to be significantly less that future without de-authorization, but more than in Alternative 1. Salinity in the basin is not likely to change significantly; there should be no positive or negative impact to fisheries from salinity changes. The six most important sport fish could be present in the same numbers as they are now. Waterfowl hunting could slightly increase under this alternative, compared to future without de-authorization. Access to fishing and hunting areas would be through bayous, canals and by way of the MRGO via boat launch ramps Cultural Resources Prehistoric Period Several prehistoric sites are located along and near Bayou La Loutre. These archaeological sites range in age from the Troyville Period, ca. A.D. 400 to A.D. 700 through the Mississippian Period, ca. A.D These time periods show an increase in population and a resulting proliferation of sites. Mound building continued but rather than used as burial mounds as in the preceding Marksville period (A.D. 200 to A.D. 400), these mounds were used as ceremonial platforms. Around 1100 A.D. in the Coles Creek, Plaquemine and Mississippian periods, large ceremonial centers were constructed with two or more large pyramidal mounds around a plaza in which they conducted religious 73

107 and civic ceremonies. During the Plaquemine/Mississippian periods, corn, squash and gourds were added to a hunting and gathering economy. Sites along Bayou La Loutre dating to the prehistoric period are 16SB91, 16SB76, 16SB142 and 16SB Modern Conditions Although people lived in the area, it was not until around 1829 and into the 1840s that U.S. surveyors began to map the area. The 1840s Plat maps show several small plantations and cabins along the southeast bank of Bayou La Loutre. The area of land around the MRGO coastward from its intersection with Bayou La Loutre does not indicate land claims or settlements although the marsh was being utilized if not permanently settled. The archaeological record along Bayou La Loutre shows historic use as early as the late 1700s. Historic sites along Bayou La Loutre are 16SB92 which consists in two historic house foundations; 16SB91 which besides a prehistoric component also contains historic ruins and one tombstone; 16SB90, a late 1700s or early 1800s cemetery; 16SB142 a scatter of historic artifacts; and an unspecified historic site, 16SB77. Oil drilling began in eastern St. Bernard Parish around the late 1930s with the construction of numerous canals such as the Bakers Canal and Engineers Canal which extend off of Bayou La Loutre. The seafood industry remains important in the area. Many of the businesses along the Bayou La Loutre and Bayou Yscloskey area harvest oyster and shrimp. Oil activity continues to occur in the area. The entire project area has been inventoried for cultural resources. In 1979, Coastal Environments, Inc. performed an inventory along the entire MRGO and identified most of the sites in the project area (Coastal Environments 1982). It is expected that Hurricane Katrina heavily damaged many of the sites in the Bayou La Loutre area. Several of the sites along Bayou La Loutre were not evaluated for National Register eligibility. These sites are: 16SB91, 16SB142, 16SB76, 16SB142, 16SB143 and 16SB77. Sites that have been determined to be not eligible to the National Register of Historic Places are: 16SB92 and 16SB90. No sites along Bayou La Loutre have been determined eligible to the National Register of Historic places Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) The Corps has met with the State Historic Preservation Office (SHPO) and determined that this action would not have an adverse effect on historic properties Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately The Corps has met with the SHPO and determined that this alternative would not have an adverse effect on historic properties. 74

108 Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately The Corps has met with the SHPO and determined that this alternative would not have an adverse effect on historic properties Aesthetics (Visual Resources) The aesthetic values of aquatic areas are usually the enjoyment and appreciation derived from the natural characteristics of a particular area. Aesthetic values found within the project area s tidal marshes apply to the quality of life enjoyed by the general public. Richard Smardon, in The Future of Wetlands Assessing Visual-Cultural Values (1983), describes how tidal marshes rate fairly high in landscape quality in comparison to other landscape types. Thus many wetland landscape types, especially open salt marshes, tend to rate highly in scenic quality in the landscape continuum. At the time of settlement, natural levee ridges bordered Bayou La Loutre and formed the major high elevation features within the project area. These levee ridges most likely appeared as linear woody vegetated islands protruding from the marsh. Ridges, intermingled with meandering water and rich, complex emergent vegetation patterns, presented ideal proportions of vegetation and open water. The variety of natural levee vegetation was mapped in an 1845 plat of a section of Bayou La Loutre. Vegetation existing then included cane, palmetto, live oak, sweetgum, hackberry, elm, ash, and wax myrtle. Profound changes in the environment brought on by natural and human activities have altered the visual surroundings of the Bayou La Loutre area. Major changes include an increase in marsh deterioration due to navigation channels, oil and gas related canals, logging canals and subsidence. These changes have resulted in the area being dominated by geometric forms and patterns not natural to the tidal marsh environment. Subsidence has greatly reduced the extent of the natural levee zone. The natural levees of Bayou La Loutre, in the area where the MRGO crosses it today, no longer support the hardwood vegetation as described in the above, but are characterized by shrubby subsiding levee vegetation including palmetto, marsh elder, sea oxeye, big cordgrass and roseau Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) Overall, some of the surrounding marsh is expected to be lost as the result of shoreline erosion. This opening of the shoreline could reduce the visual appeal of the area Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately The rock material used to construct the total closure structure would stand in contrast to Bayou La Loutre s vegetated southern levee ridge. The total closure structure would be maintained, not allowing vegetation to take hold and grow in the rock. Closing the MRGO at Bayou La Loutre could also cause an increase in erosion along Bayou La Loutre s levee ridges as recreational boat traffic would utilize it to access the Gulf of 75

109 Mexico and other points of interest. Beneficially, the rock total closure structure would serve to break up the unnatural linear southeast MRGO viewshed Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately The opening of the shoreline could reduce the visual appeal of the area compared to Alternative Navigation Prior to completion of the MRGO, navigation in the vicinity was on the GIWW, the Mississippi River, and surrounding bays, lakes, and bayous. Ocean going vessels were restricted solely to the Mississippi River. Other vessels, ranging from tugs and barges to smaller motorized and sail craft, used waterways suitable for their draft. The latest Waterborne Commerce Statistics Center (WCSC) data are available for 2005 ( and 2006 ( Traffic records from the WCSC show MRGO utilization steadily increasing until reaching a peak in terms of tonnage carried in 1978 and in terms vessel trips in Table 3.3 illustrates MRGO total domestic and foreign tonnage for the period Table 3.3 contains data with 4-year increments from and continuous records (See Appendix B). Both tonnage and total vessels have decreased since that time. Foreign-flag deep-draft vessel movements consist of self-propelled ocean-going vessels. Maximum loaded vessel drafts were approximately 36 feet with vessels taking advantage of advance maintenance and tides. For the period , approximately 20 percent of vessels traveled with loaded drafts over 30 feet. Domestic cargo on the MRGO consists of shallow-draft barge traffic and coastwise ocean-going vessels. The maximum loaded drafts for the tow vessels are 12 feet or less and domestic coastwise vessels have maximum drafts in excess of 30 feet. Comparison of tonnage volumes for the most recent period of record ( ) with the previous period ( ) shows current volumes down by nearly 60 percent, with drops in both domestic and foreign freight volumes. While total tonnage declined, the percentage of foreign freight maintained a larger share of total tonnage than domestic freight. The percentage of foreign freight represents approximately 85 percent of total tonnage. In spite of distributional changes, the overall trend illustrates a downturn for all traffic, with 2004 volumes representing an historic low before declining further in 2005 due to Hurricane Katrina. In 2006, volumes increased to greater than 2004 and 2005 volumes, but reflect a 48% decrease over 2003 levels. While the pre-katrina declines were driven by a variety of factors, the MRGO authorized depth of 36 feet, which is recognizably shallow in comparison to some other U.S. Gulf Coast deep-draft channels, and the current dimensions of the IHNC Lock, are contributors. The IHNC Lock dimensions are 640 feet by 75 feet by 31.5 feet. The limitations of the MRGO, in terms of its 36-foot depth and the IHNC Lock likely impeded commercial navigation growth during periods of significant increases in the sizes of large vessels serving U.S. ports. The 76

110 lack of funds for operation and maintenance dredging during the 1990s, and the necessity to direct funds elsewhere for emergency dredging during the pre-katrina years, is also likely to have contributed to declining trends. Annual vessel trip totals are displayed in Table 3.4, which shows that cargo vessels have predominated. The number of trips has decreased since peaking in 1982 to a greater extent than has the tonnage, representing a move toward larger ships and bigger loads. Declines in annual MRGO vessel trip counts are also, of course, directly associated with the declining tonnage volumes as shown in Table 3.5. Since its authorization, the size and draft of vessels using the MRGO has tended to increase to meet the competitive demand for more efficient movements of bulk commodities. Note: For this report, the USACE is using the definition of deep-draft vessels contained in ER This defines deep-draft as those vessels requiring greater than 14 feet. The type of cargo vessel most often found on the MRGO is one that carries dry cargo. Very few tanker vessels use the MRGO. As mentioned, cargo vessels are the predominant vessel type. Table 3.6 presents distribution of freight tonnage by approximate vessel dead-weight tonnage (DWT) range, type, and beam width. Table 3.3 MRGO Tonnage by Year (1000s short tons) Year Total Tonnage Foreign Domestic ,013 2,522 1, ,308 3,386 1, ,411 5,136 4, ,572 3,878 1, ,145 5,254 2, ,084 4,611 2, ,690 3,347 1, ,701 3,416 2, ,042 3,314 1, ,253 3,552 1, ,007 2,974 1, ,369 4, ,850 5, ,173 3, ,290 2, ,847 2, ,206 1, ,474 1, Source: U.S. Army Corps of Engineers, Waterborne Commerce Statistics Center. 77

111 Table 3.4 MRGO Number of Trips by Vessel Type ( ) Total Passenger & Cargo Tow or Barge (Dry and Liquid Year Trips Vessels (Dry and Liquid) Tugboat Cargo) ,809 1,476 1,220 2, ,941 7,551 1,837 3, ,956 11,828 1,841 4, ,419 15,084 1,190 2, ,212 1,941 1,460 2, ,479 1,486 1,110 1, ,130 3, , ,263 2, , ,934 5, ,591 3, , ,827 1, ,368 1, ,386 1, ,341 1, ,590 1, ,897 1, , ,584 1, , Source: U.S. Army Corps of Engineers, Waterborne Commerce Statistics Center. 78

112 Table 3.5 MRGO Number of Trips by Vessel Type (Selected Years) Total Passenger & Cargo Tow or Barge (Dry and Liquid Year Total Tonnage Vessels (Dry and Liquid) Tugboat Cargo) ,809 1,476 1,220 2, ,941 7,551 1,837 3, ,956 11,828 1,841 4, ,419 15,084 1,190 2, ,212 1,941 1,460 2, ,479 1,486 1,110 1, ,130 3, , ,263 2, , ,934 5, ,591 3, , ,827 1, ,368 1, ,386 1, ,341 1, ,590 1, ,897 1, , ,584 1, , Source: U.S. Army Corps of Engineers, Waterborne Commerce Statistics Center Table 3.6 MRGO Approximate Percentage of Foreign Freight by General DWT Range for Calendar Years 2000, 2002 and 2004 DWT Range Estimate % of short tons Predominate Vessel Type <10,000 16% Refrigerated Cargo Vessel 10,000-19,999 14% General Cargo, Containership 20,000-39,999 29% Containership, General Cargo 40,000-59,999 19% Containership, Chemical Carrier 60,000-75,000 22% Bulk Carrier Total 100% Source: U.S. Army Corps of Engineers, Waterborne Commerce Statistics Center Examination of the historical trends for ocean-going freight indicates general upward movement in volume of cargo per vessel trip. A general upward trend, with recognizable annual fluctuations, was evident until In addition to ocean-going freighters, a large number of tugs and towboats use the MRGO. The general increase in barge trips relative to tow trips suggests transition towards larger volumes per barge and per tow-barge movement. Tank barges of 298-foot x 54-feet are the most frequent size. The largest tows are generally 4-barge tows consisting of three 298-foot x 54-foot barges and one 150-foot x 54-foot barge pushed by towboats generally ranging from 1,800 to 3,000 horsepower. 79

113 Table 3.7 presents information about the type of commodities shipped through MRGO. In 2004 and 2006, the commodity groups with the greatest number of tons transported on the MRGO were 1) Manufactured Equipment, Machinery and Products, 2) Food and Farm Products, 3) Chemicals and Related Products. For each of the groups, foreign commerce represented more than 80% of the group total. Table 3.7 Composition of Tonnage (short tons), 2004 and Industry Group Total Domestic Foreign Total Domestic Foreign Coal 0 0% 0% 0 0% 0% Crude Petroleum 4 100% 0% 0 0% 0% Petroleum Products 44 80% 20% % 0% Crude Materials (exc. Fuels) 166 7% 93% % 79% Food and Farm Products 292 0% 100% 569 0% 100% Primary Manufactured Goods % 86% 117 3% 97% Chemicals % 82% 484 0% 100% Manufactured Equipment % 83% 22 0% 100% All Others 17 0% 100% 35 0% 100% TOTAL 1,206 13% 87% % 93% Source: U.S. Army Corps of Engineers, Waterborne Commerce Statistics Center In FY06-07, Congress did not appropriate funds for dredging the MRGO between the GIWW and the Gulf of Mexico. As a result, the controlling depth of the channel is currently approximately 22 ft. This has allowed some deep-draft and all shallow-draft traffic to continue to operate on the channel. Deep-draft vessels are entering the MRGO light-loaded, calling on tidewater port facilities in New Orleans, and exiting through the IHNC Lock into the Mississippi River for outbound voyages. Some maritime interests have reported modifying vessel operations by moving products over to Mississippi River docks for loading. Other companies have adopted other operations modifications to continue commerce. During times of extreme congestion of the IHNC Lock or when the lock is inoperable, some tows travel downstream on the Mississippi River to Baptiste Collette Bayou, exit Baptiste Collette Bayou into Breton Sound, and then enter the Inland Reach of MRGO. Eastbound tows then travel back inland on the MRGO to the GIWW Reach before continuing eastbound to locations in Mississippi, Alabama, and Florida. Westbound tows use the reverse route to avoid the IHNC Lock when it is congested or impassable. Analysis of deep-draft navigation indicates that maintaining the authorized dimensions of the MRGO between the GIWW and the Gulf of Mexico is not cost-effective. Average annual operations and maintenance (O&M) costs to dredge a single shipping lane in the MRGO Inland Reach are $12.5 million. However, maintaining a single shipping lane, which is half of the authorized dimensions, only produces approximately $3.7 million per year in transportation efficiencies. Efforts to operate and maintain the fully authorized 80

114 dimensions (i.e. a two-lane channel 500 feet wide by 36 feet deep) would be even more costly and would not produce greater navigation benefits (see Appendix C). The analysis indicates that the maintenance of a deep-draft navigation channel, of any dimension, in the MRGO between the GIWW and the Gulf of Mexico is not economically justified. The economic information available indicates that it is not cost effective to maintain shallow-draft navigation on the channel between the GIWW and the Gulf of Mexico in terms of National Economic Development (NED) criteria. The total average annual costs to maintain a 12 ft shallow-draft channel are approximately $6 million whereas the estimated average annual benefits are approximately $1.2 million Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) It is expected that a MRGO channel maintained for deep-draft navigation would allow both deep and shallow-draft traffic to return to levels just prior to Hurricane Katrina and to continue at that level in the foreseeable future Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately Complete closure of the MRGO would eliminate all deep-draft and some shallow-draft commercial traffic along the waterway between the GIWW and the Gulf of Mexico. Recreational traffic may continue to use some sections of the channel. Shallow-draft tows that traverse the IHNC Lock could not continue to use the MRGO as an alternate route during times of extreme congestion or unforeseen closures at the lock. Shallow-draft commercial traffic impacted by delays or lock closure could use some naturally deep alternative routes such as Baptiste Collette Bayou, Breton Sound and Chandeleur Sound to continue east-west traffic on the GIWW. The industry has expressed a willingness to continue working with the USACE and stakeholders to better identify these or other options Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately After some period of time, probably about 2014, the MRGO would be closed to all deepdraft and shallow-draft commercial traffic along the waterway between the GIWW and the Gulf of Mexico. After that, impacts for would be the same as Alternative 1. Recreational and commercial fishing and oil field service traffic may continue to use some sections of the channel and surrounding waterways with adequate existing draft Business The Port of New Orleans, the local sponsor, has historically dominated business activity along the MRGO. With the Mississippi River moving about 500 million tons of cargo each year including chemicals, coal, timber, iron, steel and more than half of the nation s grain exports, the Port of New Orleans is one of America s largest gateways to the global market. In 2004, Board of Commissioners of the Port of New Orleans (PONO) tenants on the IHNC (Maersk SeaLand, New Orleans Cold Storage, Bollinger 81

115 Gulf Repair, Southern Scrap, Lafarge Corp., U.S. Gypsum Co., Halliburton Inc., and Holcim Inc.), generated $5 million in annual revenues for the Board. Maritime-related industries and publicly and privately-owned facilities reliant on deepdraft access on the IHNC were profoundly impacted by Hurricane Katrina. Facilities were severely damaged and workers displaced. Disruptions were similar to those experienced by owners and employees in other business sectors affected by the storm. Two PONO tenants, Maersk SeaLand (France Road Terminal Berth 1) and CG Rail (Elaine St. Wharf), chose to discontinue operations in New Orleans and relocate to Mobile, Alabama, partly because maintained deep-draft access via the MRGO was no longer available. The USACE has no authority to compensate for these business relocations. Remaining area businesses are still involved in the process of recovery. The IHNC port area is currently in a state of flux as some businesses seek to restore normal operations, others seek to ultimately relocate due to the unavailability of deep water access to the Gulf via the MRGO and new businesses seek to locate at newly available IHNC port facilities. Businesses that rely on shallow-draft vessel operations have essentially recovered back to pre-katrina levels Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) It is expected that facilities along the IHNC that depend on deep-draft access via the MRGO would, in time, recover to business activity just prior to Hurricane Katrina Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately If the MRGO channel is blocked, some businesses in the IHNC area that depend on deepdraft access via the MRGO, may choose to relocate. Four facilities have been identified as falling into this category. The USACE has no authority to assist these businesses in relocation or to pay any costs Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately If the MRGO channel is no longer maintained between the GIWW and the Gulf of Mexico several businesses in the IHNC area that depend on deep-draft access via the MRGO may chose to reestablish their operations elsewhere. Other maritime businesses may adapt their operations practices to utilize other area waterways and transportation systems to continue to conduct commerce from their existing locations Employment Employment for Orleans Parish in the years , showed a marginal decline in the number of people employed. The figures presented in Table 3.8 indicate a 4.5 per cent decline in employment. 82

116 Employment for St. Bernard Parish in the years , showed an increase in the number of people employed. The figures presented in Table 3.8 indicate a 6.0 per cent increase in employment. Total employment for the two parishes showed an overall decline of 3.9 per cent. Table 3.8 Pre-Katrina Employment Pre-Katrina Employment Parish Orleans 259, , , , , ,260 St. Bernard 16,409 16,029 15,738 16,436 21,318 17,386 Total 275, , , , , ,646 Source: Laworks.net While overall employment declined for the two parishes, major industries utilizing the IHNC/MRGO have maintained stable employment in the years immediately proceeding Hurricane Katrina. After the hurricane, records developed for the Louisiana Recovery Authority show the impact on employment in Orleans and St. Bernard Parishes. The impact on local business activity has been devastating. Estimates show 27 percent of all Orleans Parish businesses failed after Hurricane Katrina and 42 percent of firms with five or fewer employees failed, while St. Bernard lost 54 percent of its businesses, the highest loss rate in the state (Louisiana Recovery Authority 2006). Referring to Table 3.9, as a result of Hurricane Katrina and the subsequent flooding, Orleans Parish saw an immediate decline of 63,129 jobs, or 26.2 percent loss in employment. The decline continued into November 2005, where 97,468 jobs were lost, representing a decline of 40.6 percent. Except for January 2006, there has existed a slow but steady growth in jobs, yet latest figures (June 2006) still show a 36.4 percent reduction from its pre-katrina level. St. Bernard Parish saw an immediate decline of 6,975 jobs, or 40 percent loss in employment. The decline continued into November 2005, where 11,651 jobs were lost, representing a decline of 66.7 percent. Since November 2005, there has existed a steady growth in jobs, but latest figures (June 2006) still show a 54.1 percent reduction from its pre-katrina level. Employment by the seven principle businesses located along the MRGO/IHNC has declined markedly post-katrina. Two of the seven firms have relocated outside the New Orleans area, representing a loss of 230 jobs. The remaining firms have had to adjust their employment based on the level of business they can generate given the deep-draft closure of the MRGO between the GIWW and the Gulf of Mexico and the inadequate size of the existing IHNC Lock for many ships. 83

117 Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) It is expected that employment dependent on firms located along the IHNC/MRGO area that depend on deep-draft access via the MRGO would, in time, recover to levels just prior to Hurricane Katrina. Table 3.9 Employment by Employers Subject to the Louisiana Employment Security Law Employment by Employers Subject to the Louisiana Employment Security Law Number Percent Change from Parish Month Employed Previous Month August 2005 Orleans July ,175 August , % September , % -26% October , % -40.4% November , % -40.6% December , % -38.1% January , % -42.8% February , % -41.0% March , % -38.6% April , % -38.4% May , % -37.6% June , % -36.4% St. Bernard July ,569 August , % September , % -40% October , % -66.1% November , % -66.7% December , % -65.2% January , % -60.5% February , % -60.0% March , % -58.5% April , % -56.4% May , % -55.5% June , % -54.1% Source: Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately Firms dependent on deep-draft access via the MRGO could relocate if the channel is blocked between the GIWW and the Gulf of Mexico.. If firms were to relocate within the New Orleans geographic area, there would be little change in post-katrina employment. If the firm were to relocate outside of the New Orleans area, local unemployment would increase. 84

118 Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately Without an authorized and maintained deep-draft MRGO channel between the GIWW and the Gulf of Mexico, businesses in the area may chose to modify their employment practices or they may chose to move their companies elsewhere. If firms chose to relocate within the New Orleans geographic area, there would be little change in post- Katrina employment. If firms chose to relocate outside of the New Orleans area, local unemployment would increase Community Cohesion Prior to Hurricane Katrina, political leaders and residents of St. Bernard Parish have petitioned for the closure of the MRGO, citing concerns over erosion, loss of wetlands and hurricane protection, particularly with respect to storm surges. Hurricane Katrina caused tremendous damage to five parishes in the Greater New Orleans area. Many residents of the affected areas, especially St. Bernard and Orleans Parishes, identify storm surge along the MRGO as the cause for the devastating damage to their property and lives. Flooding resulted in the loss of life, property damage, business losses, and the relocation of residents. Many residents of affected communities have joined together to call for the closure of the MRGO channel Future Without De-authorization Conditions (continuation of the existing deepdraft channel with authorized width) Residents of the affected areas of Orleans and St. Bernard Parishes would continue to argue for the closure of the MRGO, citing damages they attribute to the storm surge that occurred during Hurricane Katrina Alternative 1 Construct a Total Closure Structure Across the MRGO Near Bayou La Loutre Immediately A majority of the residents living in affected areas of Orleans and St. Bernard Parishes would likely agree that an immediate closure of the MRGO would provide the greatest level of protection for their communities Alternative 3 - Cease All MRGO Operations and Maintenance Dredging Activities Immediately While discontinuance of dredging would alleviate the concerns of some residents of the affected areas of Orleans and St. Bernard Parish, many would continue to argue for an immediate closure of the MRGO, maintaining that the waterway remaining open for some period of time would still represent a threat to their communities. 3.3 COMPARISON OF IMPACTS Table 3.10 provides a summary of the environmental impacts evaluated in this document. 85

119 Table 3.10 Comparison of Impacts Significant Resource Existing conditions Future-without deauthorization. Alternative 1 Total Closure Alternative 3 All operations and maintenance ceased Water Quality Salinity Construction of MRGO and other factors increased salinity in Pontchartrain Basin. Salinity should stay stable in Mid-Basin and might increase in Lower Basin as land loss from various causes continues. Slightly reduced salinity throughout project area soon after closure. Modeling indicates greatest reduction could be at Alluvial City ppt. Salinity stratification north of the structure would be reduced and it is expected that the size of the H-A zone could shrink. Salinity unlikely to become lower for several years until much of the channel shoals Vegetation - Wetland Loss From 1956 to 1990, approximately 68,660 acres of wetlands were lost in the Project Area. Approximately 91 acres of wetlands are lost per year on the unprotected north bank of the MRGO due to erosion. About 38 acres of wetlands were created yearly by beneficial use of dredged material before Katrina. Wetlands could be created when the channel is dredged to authorized dimensions and more wetlands could be created each year. These could be lost at the background loss rate of the area and at the end of 50 years there could be 2,702 acres of created wetlands remaining. Erosion on the north bank is likely to cause the loss of 4,565 acres of marsh. Net loss over 50 years could be 2,343 acres of marsh. There would be no beneficial use dredged material to create marsh. Removal of deep and shallow-draft vessels is anticipated to reduce the erosion of marsh on the north bank. Marsh loss could be decreased by a significant percentage of the 2,343 acre net loss of the future without. More marsh loss than Alternative 1, but probably significantly less than future without. Vegetation Habitat Type Wetland habitat types generally determined mainly by salinity. Drought, and human-induced causes can change habitat type. Habitat types are expected to generally remain as they are at present. Saline marsh could move north along the MRGO. No large-scale change in vegetation type. It is possible that the Lake Borgne Land Bridge could change from saline marsh to brackish marsh. Central Wetlands could possibly have more intermediate marsh and cypress. Habitat types are expected to remain generally as they are at present. Wildlife Wintering waterfowl and furbearers have declined since about 1970, however are still present. Estimated loss of marsh could reduce numbers of waterfowl, furbearers and other wildlife that are marsh-dependent Reduction in marsh loss could increase abundance of marshdependent wildlife compared to the future without. Reduced salinity north of the closure could improve the area slightly for waterfowl. Less of an increase of marsh-dependent wildlife than Alternative 1. Habitat for waterfowl and furbearers is anticipated to stay as it is now. Fisheries Fish After about 1970, 22 species of freshwater fish were Could be slight decline in estuarinedependent fish due to marsh loss. 86 Could be slight increase in estuarine-dependent fish compared Slightly less increase in estuarinedependent fisheries when compared to

120 Significant Resource Existing conditions Future-without deauthorization. Alternative 1 Total Closure Alternative 3 All operations and maintenance ceased and Shellfish apparently no longer found in the Biloxi Marshes/Lake Borgne area. However six important sport fish seemed to be present in approximately the same numbers as prior to about H-A zone in Lake Pontchartrain causes reduced benthic community during the H-A event. Salinity should not change significantly so fishery distribution might remain approximately as at present. Six most important sport fish could be present in approximately the same numbers as exist now. It is likely that the H-A zone in Lake Pontchartrain could remain as it is at present. to the future without. Fish have alternate routes, so passage up and down the MRGO should not be blocked by closure. Six most important sport fish should be present in approximately the same numbers as exist now. Salinity stratification would be reduced north of the total closure which is expected to allow the H-A zone in Lake Pontchartrain to shrink. Large Rangia and other benthos could colonize the area which should lead to increased fishery production in a portion of the lake. the future without than Alternative 1 Six most important sport fish should be present in approximately the same numbers as exist now. Large Rangia clams and other benthos expected to remain absent from the H-A zone. fisheries in lake could remain as they are today. Essential Fish Habitat (EFH) MRGO channel, adjacent waters and marshes and Lake Pontchartrain are EFH Bottom habitat in MRGO would be temporarily disturbed by dredging. Possible net loss of 2,343 acres of marsh which is valuable EFH. Less than 17 acres of EFH on the bottom of the MRGO would be destroyed by the closure structure. There are alternate routes so passage of managed species up and down the MRGO might not be blocked by the closure. It is possible that this alternative could have significantly less loss of marsh EFH than the future without. Compared to future without, this alternative is expected to significantly decrease future marsh EFH loss, but decrease is not likely to be as much as that in Alternative 1. Threatened and Endangered Species (T&E) Brown pelicans have not nested on Breton Island in the recent past. Beneficial use has nourished Breton Island and piping plovers have utilized the island. Sea turtles in agreed-upon numbers have been taken in the Bar Channel. Detailed contract specifications to protect the sturgeon, manatee and sea turtles have been used. Maintenance of the channel did not adversely affect T&E species. Brown pelicans have not nested on Breton Island in the recent past. Piping plovers might occasionally use Breton Island. Sea turtles in agreed-upon numbers might continue to be taken in the Bar Channel. Detailed contract specifications to protect the sturgeon, manatee and sea turtles would continue. Maintenance of the channel should not adversely affect any T&E species. Brown pelicans have not nested on Breton Island in the recent past. Piping plovers occasionally use Breton Island. There are nearby habitats that might be similar to Breton Island. No sea turtles would be taken in the Bar Channel. Alternate routes are available so passage for sturgeon, manatee and sea turtles should not be blocked by closure structure. Detailed contract specifications to protect the manatee and sturgeon would continue. Every effort would be made to construct the closure during the May through September window when the This alternative is not likely to adversely affect any endangered or threatened species. 87

121 Significant Resource Natural and Scenic Rivers Existing conditions Seven scenic bayous in project area. Future-without deauthorization. Alternative 1 Total Closure sturgeon are in the rivers. The closure structure is not likely to adversely impact any T&E species.. No impact. No impact. No impact. Alternative 3 All operations and maintenance ceased Air Quality St. Bernard Parish classified in attainment of all NAAQS. Ambient air quality is likely to be temporarily impacted during dredging. Ambient air quality is likely to be temporarily impacted during construction. No impact. Recreation Fewer freshwater fish present after about Six most important sport fish present in good numbers. Waterfowl hunting less productive than before about 1970 in St. Bernard Parish Hunting and fishing could slightly decrease due to anticipated marsh loss. Waterfowl hunting and estuarine dependent fishing could be slightly positively impacted compared to the future without. Salinity above La Loutre ridge unlikely to change, thus hunting and fishing success could be less than Alt. 1 Cultural Entire area in vicinity of closure has been inventoried. USACE has met with SHPO and determined that maintenance of the channel would not have an adverse effect on historic properties. USACE has met with SHPO and determined that construction of the closure would not have an adverse effect on historic properties. USACE has met with SHPO and determined that this alternative would not have an adverse effect on historic properties. Aesthetic Natural levee ridges of Bayou La Loutre have subsided and no longer support the trees they once did. Marsh has been lost due to channels, canals and subsidence. Area now dominated by forms not natural to the tidal marsh environment. General loss of marsh could occur, reducing visual appeal. The closure structure could cause an unnatural break in the vegetated La Loutre ridge. The closure structure should serve to break up the unnatural linear southeast MRGO viewshed. There would be no structure to cause an unnatural break or break up the unnatural viewshed. Navigation MRGO tonnage peaked in 1978, trips in In 2004 tonnage was 13% of that in 1978 and trips were14% of Deep- and shallow-draft traffic would return to pre-katrina levels. Both deep-draft and shallow-draft shipping would be eliminated. Shallow-draft tows that use MRGO as an alternate route when the IHNC is congested or unexpectedly closed could no longer do so. Shallow-draft could continue until about Then impacts would be the same as Alt. 1 88

122 Significant Resource Existing conditions Future-without deauthorization. Alternative 1 Total Closure Alternative 3 All operations and maintenance ceased Business Katrina stopped deep-draft access, except through the IHNC Lock, many maritime related businesses in area severely impacted. Two chose to relocate to Mobile. Others are trying to recover; some may plan to relocate. Shallow-draft facilities essentially recovered. Post-Katrina 230 jobs lost from MRGO-IHNC area due to relocation and other businesses downsizing. Orleans Parish shows 34.6% reduction from pre-katrina jobs and St. Bernard shows 54.1% reduction. Facilities along the IHNC that rely on deep-draft would, in time, recover to pre- Katrina levels. Businesses that depend on deepdraft may choose to relocate. Businesses that rely on shallow-draft would have the added expense of using the Mississippi River to access their facilities. The USACE has no authority to relocate impacted businesses. Businesses that depend on deep-draft may choose to relocate. Businesses that rely on shallow-draft would have the added expense of using the Mississippi River to access their facilities about The USACE has no authority to relocate impacted businesses. Employment In general, Orleans and St. Bernard Parishes may never return to pre-katrina employment. Employment in MRGO- IHNC area should, in time, recover to pre-katrina levels. More deep-draft firms would relocate, if in New Orleans, no impact; if outside, loss of employment. Shallow-draft firms might use the Mississippi River or relocate. More deep-draft firms would relocate, if in New Orleans, no impact; if outside, loss of employment. After 2014, shallow-draft firms might use the Mississippi River or relocate Community Cohesion Many residents of St. Bernard and Orleans blame MRGO for storm surge that did devastating damage to property and lives. Majority demanding closure. Residents of St. Bernard and Orleans would continue to vociferously demand closure. Majority of residents of St. Bernard and Orleans Parishes would continue to be concerned about presence of MRGO. Most residents of St. Bernard and Orleans would agree that closure would provide the greatest protection to their communities While discontinuance of dredging would alleviate concerns of some, majority would continue to vociferously demand closure 89

123 3.4 CUMULATIVE EFFECTS ANALYSIS Cumulative Effects Background The primary goal of cumulative effects analysis (CEA) is to determine the magnitude and significance of the environmental consequences, adverse or beneficial, of the proposed alternatives in the context of the cumulative effects of other past, present, or reasonably foreseeable future actions. The spatial component considered for this CEA is within the Pontchartrain Basin as depicted on Figure 3.2. The portion of the boundary illustrated around Lake Pontchartrain essentially represents the transition between non-estuarine and estuarine influenced habitat. The remaining boundary was determined by identifying physical barriers (such as a ridge or levee) and the open waters of Breton Sound that have been impacted directly through the operation and maintenance of the navigation channel in Breton Sound (represented by the dashed line). The temporal component to be considered for this CEA is the beginning of construction of the MRGO in the early 1960 s through a typical USACE fifty year project evaluation period. A qualitative checklist for the identification of potential cumulative effects of the Future Without alternatives as well as alternatives 1 and 3 of this proposed legislative action are included as Tables 3.11, 3.12, and 3.13 respectively. Cost considerations and technical limitations preclude the USACE from obtaining the information necessary to quantify cumulative impacts to any significant resource. However, in this case, a qualitative analysis of cumulative impacts is sufficient to inform a reasoned choice among alternatives. The use of a plus/minus system as a gauge is based upon best professional judgment and knowledge of past, present and reasonably foreseeable future actions within the described and illustrated spatial boundary. A key is included in Tables 3.11, 3.12, and 3.13 describing relative potential for beneficial or adverse impacts. This checklist approach to analyzing cumulative impacts is an accepted methodology described further in the 1997 CEQ handbook for Considering Cumulative Effects Under the National Environmental Policy Act (Appendix A). 90

124 Table 3.11 Checklist for Identification of Cumulative Effects of Future Without Alternative Checklist for Identification of Cumulative Effects of the Future Without Alternative. Future Without Potential Impact Area Construction Operation Past actions Other Present Actions Future Actions Cumulative Impact Water Quality = = + = Fisheries = = = Wetland Vegetation Wildlife = = + - Essential Fish Habitat Threatened and Endangered Species = = = Natural and Scenic Rivers = = = = = = Air Quality = = = = = = Recreation Cultural = = = Aesthetics = = Navigation = = = Economics = = = + + = Key: - low adverse effect -- moderate adverse effect --- high adverse effect = no effect + low beneficial effect ++ moderate beneficial effect +++ high beneficial effect 91

125 Table 3.12 Checklist for Identification of Cumulative Effects of Alternative 1 Checklist for Identification of Cumulative Effects of Alternatives 1. Alternative 1 Potential Impact Area Construction Operation Past actions Other Present Actions Future Actions Cumulative Impact Water Quality = = Fisheries = Wetland Vegetation Wildlife = = Essential Fish Habitat - = Threatened and Endangered Species = = = Natural and Scenic Rivers = = = = = = Air Quality = = = = = = Recreation - = = Cultural = = = Aesthetics = = = Navigation = = = Economics = = Key: - low adverse effect -- moderate adverse effect --- high adverse effect = no effect + low beneficial effect ++ moderate beneficial effect +++ high beneficial effect 92

126 Table 3.13 Checklist for Identification of Cumulative Effects of Alternative 3 Checklist for Identification of Cumulative Effects of Alternative 3. Alternative 3 Potential Impact Area Construction Operation Past actions Other Present Actions Future Actions Cumulative Impact Water Quality = = ++ + Fisheries = = Wetland Vegetation = Wildlife = = Essential Fish Habitat - = Threatened and Endangered Species = = = Natural and Scenic Rivers = = = = = = Air Quality = = = = = = Recreation - = = Cultural = = = Aesthetics = = = Navigation = = = Economics = = Key: - low adverse effect -- moderate adverse effect --- high adverse effect = no effect + low beneficial effect ++ moderate beneficial effect +++ high beneficial effect Past actions within the spatial and temporal boundaries identified include construction of the MRGO navigation in the early 1960 s, maintenance and operation of the channel, and environmental restoration projects in proximity to the channel. Other present and future actions (those projects authorized and/or funded) within the spatial and temporal boundaries identified, include projects planned for coastal environmental improvements that are a part of the Coastal Impact Assistance Program, CWPPRA, and proposed measures to be undertaken pursuant to the authorization provided under the heading Operation and Maintenance in Title I, Chapter 3 of Division B of Public Law , as modified by Section 2304 in Title II, Chapter 3 of Public Law Additional future actions within the spatial and temporal boundaries identified possibly include projects approved as a part of LCA and the potential for increased hurricane protection enhancement in the vicinity of the Inner Harbor Navigation Canal (Public Law ). Plans, or alternatives, being developed and analyzed through LACPR will be presented to Congress. An associated programmatic environmental impact statement is currently being prepared. Due to the current status of the LACPR effort, it is worth mentioning in cumulative effects. However, because of the speculative nature of the LACPR, the alternatives will not be included in this analysis. 93

127 Additionally, the state of Louisiana has developed and adopted a conceptual state master plan for the protection and restoration of coastal Louisiana called Louisiana s Comprehensive Master Plan for a Sustainable Coast. Because the state master plan has been adopted by the state of Louisiana it must be noted within the context of CEA. However, the state master plan is conceptual and subject to change on an annual basis. Although the document describes implementation, it is not clear what mechanisms, particularly state action and funding, would be used to actually implement any measures. Therefore, the inclusion of the state master plan in this CEA is noted, but the effects of any proposed recommendations are not included in determining the outcome of cumulative effects Summary of Cumulative Effects. Future Without De-authorization No real change or adverse environmental cumulative effects are anticipated for all resources, except for wetland vegetation, are anticipated. The reasoning, or rationale, for assigning low beneficial cumulative effects for the resources just mentioned is the additive effect of past and present actions combined with this alternative. It is estimated that the Future Without alternative is unlikely to influence salinity or marsh vegetation types or reduce the H-A zone in Lake Pontchartrain. However, ecosystem restoration measures, such as a freshwater diversion structure at Violet, could be more difficult to implement than under Alternative 1. For example, without a structure in the MRGO channel, a much larger freshwater diversion would be required at Violet, which would increase cost significantly and decrease the ability to control desired environmental results within the greater Pontchartrain Basin. Overall, the potential cumulative impact for the Future Without alternative is unchanged, or slightly negative. Alternative 1 Positive environmental cumulative effects are anticipated for water quality, fisheries, wetland vegetation, essential fish habitat, and economics. For water quality and wetland vegetation, the cumulative effects would be moderately beneficial primarily due to potential future projects within the spatial boundary that would be conducive for improving water quality and wetland vegetation resources. For instance, a proposed diversion from the Mississippi River in the vicinity of Violet, Louisiana would direct freshwater into an area north of the closure structure. The combined action of the total closure and the diversion would likely further reduce salinities north of the structure. This salinity reduction could promote the re-growth of Cypress in the Central Wetlands and the re-establishment of fresh and intermediate marsh in some proximity to the diversion outfall and the closure structure. The rationale for not assigning a high beneficial effect as a result of cumulative effects is due to other past (i.e., construction of the MRGO) or present actions (i.e., no beneficial use of dredge material due to no dredging of the MRGO) actions that have had or continue to have an adverse effect or no effect at all on these particular resources. Furthermore, the same reasoning can be applied to the remaining resources receiving a low beneficial effect (fisheries, essential fish habitat, and economic resources). Those resources received a low beneficial 94

128 cumulative effect not because future projects potentially provide a lower cumulative effect, but because of past (i.e., construction of the MRGO) and present actions (i.e., no beneficial use of dredge material due to no dredging of the MRGO) within the temporal boundary of the CEA. Overall, the potential cumulative impact for Alternative 1 is a slightly beneficial effect. Alternative 3 Positive environmental cumulative effects are anticipated for water quality, wetland vegetation, and economics. The reasoning, or rationale, for assigning low beneficial cumulative effects for the resources just mentioned is the additive effect of past and present actions combined with this alternative. It is estimated that Alternative 3 is unlikely to influence salinity or marsh vegetation types or reduce the H-A zone in Lake Pontchartrain until the MRGO channel has shoaled sufficiently enough to limit tidal flows. Cumulative impacts for all other resources would be expected to remain nearly the same over the same period of evaluation. Overall, the potential cumulative impact for Alternative 3 is unchanged, except for the resources identified earlier in this paragraph. Figure 3.2 CEA Spatial Boundary 95

129 SECTION 4 PUBLIC AND AGENCY INVOLVEMENT 4.1 INTRODUCTION This section documents details of the study s public involvement and coordination efforts with Federal, state, local agencies and entities, parishes, and other interested parties. Chapter 5 describes the study s compliance with environmental requirements, including coordination with the U.S. Fish and Wildlife Service. Scoping is not required for a LEIS, however, in conducting this study the USACE emphasized efforts to allow open and broad participation in the planning process. Federal, state and local government parties and other organizations were invited to help formulate plans for de-authorization of the MRGO and environmental restoration in the area influenced by the MRGO. Several groups did develop such plans. A public meeting was held on October 18, 2006 to present the study process and accept comments. Another public information meeting was held on May 19, 2007 to present alternatives evaluated in detail and the Recommended Plan and to accept questions and comments. All comments made during the 45-day public comment period will be incorporated into an Addendum to the LEIS. In addition, there is an interactive web page ( that provides a library of project information, materials from stakeholder meetings, and a comment button allowing the public to submit questions or information to the study team. 4.2 STAKEHOLDER PARTICIPANTS Stakeholder participants included, but were not limited to: St. Bernard Parish Governor s Office of Coastal Activities Governor s Advisory Commission on Coastal Restoration and Conservation Louisiana Coastal Protection and Restoration Authority Louisiana Department of Natural Resources Louisiana Department of Transportation and Development Louisiana Department of Wildlife and Fisheries Environmental Protection Agency United States Coast Guard Maritime Administration (MARAD) United States Fish and Wildlife Service Port of New Orleans Gulf Intracoastal Canal Association Lake Pontchartrain Basin Foundation Coalition to Restore Coastal Louisiana Gulf Restoration Network American Rivers Sierra Club Biloxi Marshlands Corporation 96

130 Steamship Association of Louisiana Gulf States Maritime Association Bring New Orleans Back Commission New Orleans Business Council LSU Hurricane Center National Aeronautic and Space Administration Sierra Club Lake Borgne Basin Levee District Levees.org National Wildlife Federation Louisiana Wildlife Federation Southeast Louisiana Flood Protection Authority-East Environmental Defense National Audubon Society The Nature Conservancy Federal Emergency Management Agency Louisiana Environmental Action Network City of New Orleans Local and regional businesses Private citizens 4.3. STAKEHOLDER MEETINGS During 2006, USACE, New Orleans District held a series of eight public stakeholder forums to identify various plans and proposals for the future of the MRGO. Meetings included technical presentations and open discussions on topics including wetlands, navigation, storm protection, and the local economy. Each stakeholder group was invited to make detailed presentations on any plans they developed. Four stakeholder groups (St. Bernard Parish, Lake Pontchartrain Basin Foundation, Bring New Orleans Back Commission and Biloxi Marshlands Corporation) submitted their plans for consideration in development of the Interim Report. These plans included measures to close or modify the MRGO, for hurricane protection and for coastal restoration. These plans are described later in Section 4. In the end, there were 16 consensus measures supported by many stakeholders (see Section 4.4.5). However, the different stakeholders could not agree on a comprehensive plan to close the channel. Their recommendations varied from total closure to a sector gate with a draft of 28 feet. Many of the measures from the stakeholder plans were incorporated into the Interim Report to Congress. A ninth stakeholder forum was held on April 16, 2007, following the release of the Interim Report to Congress and publication of the Notice of Intent to prepare a LEIS. Navigation interests were concerned that none of the alternatives evaluated in detail maintained continued shallow-draft navigation. They were disturbed there would no longer be an alternate route when the IHNC Lock was congested or be inoperable. On the other hand, St. Bernard Parish officials spoke out very strongly in favor of total closure as soon as possible. The representative from the Holy Cross Neighborhood Association did not want the IHNC Lock Replacement fast tracked as part of the MRGO de-authorization. 97

131 Another stakeholder forum was held on May 8, At that meeting the USACE team provided an overview of preliminary details developed on each of the alternatives evaluated in detail. In addition, the USACE announced a target report and LEIS completion schedule and provided an update on the ongoing in-house review of the draft Final Report to Congress and draft LEIS. Stakeholders from the shallow-draft navigation industry made brief comments on the direction of the study and asked for consideration for an emergency alternative navigation route in times of high congestion or prolonged maintenance of the IHNC Lock. Stakeholders from St. Bernard Parish offered some potential alternative routes. The USACE agreed to facilitate further discussions between the parties with the goal of resolving the issue prior to completion of the Final Report to Congress. 4.4 STAKEHOLDER PLANS The State of Louisiana, Federal agencies, environmental organizations, planning groups, businesses, and individuals have developed plans for coastal protection and restoration that include MRGO related components. In some cases, the plans are specific to the MRGO area; in others, the channel is merely a component of larger proposals. In conducting this study the USACE invited stakeholders to present their plans as part of efforts to identify common approaches to help achieve consensus. The following non- Federal plans and studies are highlighted given their relevance to this de-authorization study St. Bernard Parish Plan The features of the St. Bernard Parish Plan in the vicinity of MRGO are summarized below and the plan is available on the internet at 1) Construct Five Floodgates: at Seabrook, on the GIWW, on MRGO near Bayou Bienvenue, on Bayou Dupre at Lake Borgne, and on the MRGO near Verret. 2) New Bankline Stabilization on the entire shore of Lake Borgne. 3) Breakwaters in Lake Borgne. 4) Restore La Loutre Ridge to +8 feet. 5) Total Closure of MRGO by a structure at the Bayou La Loutre Ridge. 6) Rock Dike Closure of MRGO near Lake Athanasio. 7) Total Closure of Alabama Bayou at MRGO. 8) Freshwater Diversion from Mississippi River at Violet and another site. USACE Comments on the above measures: 1) Some of these are being considered under other efforts to improve IHNC storm protection. 2) Stabilization on some of the shore of Lake Borgne is proposed as part of operation and maintenance activities authorized under Public Law ) These are being considered under LACPR. 4) This is being considered under LACPR. 5) This is the Recommended Plan. 98

132 6) The USACE proposes that only one structure on the MRGO near Bayou La Loutre is needed (see discussion of evaluation and elimination of Interim Report Alternative 2b in Sections 2.2 and 2.4 of this report). 7) This is being considered under LACPR. 8) This is being considered under LACPR. Other Features Construct new levee connecting the five proposed floodgates on the GIWW and MRGO to existing levees on the SW shore of MRGO to +17 feet. No Closures at Rigolets and Chef Pass. Raise levee that is parallel to the SW shoreline of the MRGO to feet and other levees surrounding the Parish to +20 feet. Construct New Levee connecting the southernmost levees in the Parish to existing levees on the Mississippi River. Height should be feet. Continue construction of 40 Arpent Levee through Verret. Raise Both Sides of River Levee. Construct New River Floodgate at Bohemia. Remove Old Grand Prairie Levee. Biloxi Marsh Restoration Plan with measures to protect and enhance existing marsh as well as create additional marsh. Dredge and maintain Baptiste Collette Bayou. Construct new channel from Baptiste Collette Bayou to Gulfport Ship Channel. Restore Breton and Chandeleur Island Chain with dredged material from proposed channel. Breakwaters to protect the Chandeleur Islands. USACE Comments on the above measures: These are being considered under LACPR LAKE PONTCHARTRAIN BASIN FOUNDATION PLAN The Lake Pontchartrain Basin Foundation (LPBF) has developed a comprehensive habitat management plan that includes measures related to the MRGO. Those features are highlighted below and the full plan is available on the internet at 1) Constriction of the MRGO channel at the Bayou La Loutre Ridge to 12 feet by 125 feet. 2) Restoration of Bayou La Loutre ridge. 3) Introduction of freshwater into the system through a diversion off the Mississippi River at the Violet Canal. 4) Armoring of eroding shorelines on the north bank of MRGO and on Lake Borgne 5) Reduction of ship speed on the Inland Reach. 6) Constriction of Bayou Dupre at Lake Borgne. 7) Utilization of previously dredged material for marsh creation. 8) A sill at Seabrook. 9) Discontinuation of advanced maintenance on the MRGO. 10) Utilization of dredged material in a beneficial manner. 99

133 USACE comments on the above measures: 1) This plan was eliminated from further study because shallow-draft is not economically justified. 2) This is being considered under LACPR. 3) This is being considered under LACPR. 4) Stabilization on some of the shore of Lake Borgne is proposed as part of operation and maintenance activities authorized under Public Law ) Under the Recommended Plan, this is probably not necessary. 6) This is being considered under LACPR. 7) This is being considered under LACPR. 8) This is being considered under other efforts to improve the Inner Harbor Navigation Canal storm protection. 9) Under the Recommended Plan, this is not necessary. 10) This is being considered under LACPR Bring New Orleans Back Commission Plan The features of the Bring New Orleans Back Commission recovery plan located near MRGO are summarized below and the plan is available on the internet at 1) Sector gates Seabrook, GIWW, and MRGO at Bayou Dupre with leaky levee between the latter two. 2) Heightening and armoring of existing levees on the MRGO. 3) A new levee on the eastern shore of the MRGO or the placement of surge barriers across Lake Borgne. 4) A normally closed deep-draft sector gate in the MRGO with a draft of approximately 28 feet. 5) Reintroduction of freshwater. 6) Rebuilding the La Loutre landbridge. 7) Restoration of the Biloxi Marsh. 8) Armoring the MRGO banks to stop erosion. 9) Aggressive use of dredged material to build land. 10) Vessel speed control. USACE comments on the above measures: 1) This is being considered under the Inner Harbor Navigation Canal Floodgates Conceptual Study, ) This is being considered under LACPR. 3) These are being considered under LACPR. 4) The Recommended Plan is a total closure structure near Bayou La Loutre. 5) This is being considered under LACPR. 6) This is being considered under LACPR. 7) This is being considered under LACPR. 8) This is being considered under LACPR. 9) This is being considered under LACPR. 100

134 10) Under the Recommended Plan, this is probably not necessary Biloxi Marshlands Corporation Plan A private company, the Biloxi Marshlands Corporation, owns large tracts of wetlands in the vicinity of the MRGO and has developed a conservation and management plan for their holdings. Features of the company s plan in the vicinity of MRGO are summarized below and the plan is available on the internet at 1) Bayou La Loutre Ridge bank armament on both sides of the bayou. 2) Marsh creation and terracing. 3) Two water control structures in the MRGO. 4) Ridge refurbishment. 5) Vegetative plantings. 6) Massive freshwater diversion. 7) Restore the MRGO to original 500-ft width and fill the rest. USACE comments on the above measures: 1) This is being considered under LACPR. 2) This is being considered under LACPR. 3) The USACE proposes that only one structure on the MRGO near Bayou La Loutre is needed (see discussion of evaluation and elimination of Interim Report Alternative 2b in Sections 2.2 and 2.4 of this report). 4) This is being considered under LACPR. 5) This is being considered under LACPR. 6) This is being considered under LACPR. 7) This is infeasible from an engineering viewpoint because it would involve 45-foot or longer sheet piles to keep the fill out of the reduced channel. It is also prohibitively expensive. Other features of the Biloxi Marshlands Corporation Plan: Chandeleur Islands: annual vegetative plantings, introduction of sediment to the system, and the use of breakwaters, groins, and shoreline armoring to protect the existing islands. Northeastern Outlying Islands: bank armament and vegetative plantings and marsh creation/nourishment. Lower Biloxi Marsh: water control structures, bank armament, marsh creation, terraces, and vegetative plantings. Upper Biloxi Marsh: bank armament, marsh creation, terracing, and vegetative plantings of areas impacted by muskrat. USACE Comments on the above measures: These are being considered under LACPR Stakeholder Consensus Items The four previously identified stakeholders, as well as members of industry, met after their individual plans were developed. Many of the non-federal interests including the Coalition to Restore Coastal Louisiana (CRCL) identified opportunities for consensus. 101

135 These items take into consideration a priority for public safety, while also including opportunities for ecosystem restoration and protection as well as economic development. The consensus items include: 1) Overall, establish Habitat Goals of returning the landscape to historic ( ) pre-mrgo conditions (strategies to return wetlands to pre-mrgo conditions). 2) Restore Bayou La Loutre Ridge east of the MRGO to Christmas Camp Lake with introduced sediment and replanting of forest. 3) Something located in the MRGO at the Bayou La Loutre Ridge. There were numerous suggestions but no consensus as to what this something needs to be. 4) Restoration and protection of the Chandeleur Islands with beach nourishment and armoring. 5) Restoration and protection of the Biloxi Marsh through introduction of sediment and armoring. 6) River reintroductions including one at or near the site of the current Violet Canal. 7) Long distance transport of sediment via pipeline for purposes of land restoration throughout the project area. 8) Improve existing levees, armor them (MRGO levee including banks), increase height where needed and protect them with restored marsh (marsh aprons). 9) Storm breakwaters constructed from the Golden Triangle to Bayou St. Malo. 10) Shoreline protection from the Golden Triangle to Bayou St. Malo. 11) A levee constructed from approximately Verret to the GIWW including protecting the land of the Golden Triangle. 12) Assured maintenance of MRGO by the Federal Government to new authorized draft. 13) No gate constructed across the MRGO/GIWW at Paris Road. 14) Fully fund a deep-draft lock at the IHNC and fast track this project to provide access for navigation to businesses currently relying on the MRGO. 15) Find relocation funding for existing businesses that currently rely on the MRGO. 16) Subsidize businesses until fixes are in place. USACE comments on the above measures: The following stakeholder consensus items are being considered for incorporation into the LACPR: 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, and 14. 3) The something is now a total closure structure near Bayou La Loutre under the Recommended Plan. 12) Under the Recommended Plan, this is probably not necessary. 13) Locations are being considered under the Inner Harbor Navigation Canal work authorized in Public Law for storm protection. 102

136 4.5 FINAL INTEGRATED ECOSYSTEM RESTORATION AND HURRICANE PROTECTION: LOUISIANA S COMPREHENSIVE MASTER PLAN FOR A SUSTAINABLE COAST, 2007 Immediately construct a closure dam at Bayou La Loutre that will restore the integrity of the Bayou La Loutre ridge. This will affect both the shallow-draft and deep-draft navigation industries, and a comprehensive closure plan should include mechanisms to mitigate the economic consequences for users that rely on the channel. However, these considerations should not in any way delay the channel s immediate closure. In addition, actions must be taken to avoid increased erosion in nearby waterways should shallowdraft and recreational traffic circumvent the closure structure. Ensure that the channel remains isolated from Lake Borgne so that the channel may convey fresh water from the Mississippi River to the Biloxi Marshes and other areas of St. Bernard Parish. Without such a freshwater conduit, these marshes will not receive wetland building fresh water and sediment. Restore wetlands and swamps in the Central Wetlands and Golden Triangle areas. Integrate this MRGO closure plan with overall hurricane protection plans for the New Orleans metropolitan area. In Appendix A of the report, the following statement is found: This measure will close the MRGO at the Bayou La Loutre Ridge with an earthen plug. The MRGO begins at the confluence of the Gulf Intracoastal Waterway (GIWW) and the Inner Harbor Navigation Canal (IHNC) and extends southeastward through the Breton/Chandeleur Sound to the Gulf of Mexico. Appropriate economic mitigation plans must be implemented to address impacts to deep-draft and shallow-draft navigation facilities and industries. In addition, actions must be taken to avoid increased erosion in nearby waterways should shallow-draft and recreational traffic circumvent the closure structure. If at any time after the channel is closed with an earthen plug it is decided to restore limited navigation capacity, any new navigation structure to be constructed would be closed under normal conditions in order to maintain the integrity of the Bayou la Loutre Ridge. The lock structure would be operated only under emergency situations and only for shallow-draft traffic. USACE comments on the above measures: 1) The Recommended Plan is a rock total closure structure near Bayou La Loutre. 2) Some stabilization of the MRGO and Lake Borgne shoreline is proposed as part of operation and maintenance activities authorized under Public Law as is marsh creation on the landbridge between the MRGO and Lake Borgne. 3) Marsh creation in the Golden Triangle is proposed as part of operation and maintenance activities authorized under Public Law Wetland restoration in the Central Wetlands is being considered under LACPR. 4) This is being considered under LACPR. 103

137 4.6 MISTER GO MUST GO PLAN This report, authored by Drs. John Day and Paul Kemp of LSU, Dr. Mark Ford of CRCL, and Dr. John Lopez of the LPBF was presented to the USACE in December 2006 as a guide for the Congressionally directed closure of the MRGO. The report says that construction of MRGO destroyed and continues to destroy the natural hurricane buffer provided by wetlands and cypress forests. The report claims that MRGO exacerbated Hurricane Katrina s damage by increasing the height and speed of the storm surge and facilitated wave attack on exposed levees. The report proposes the following plan for deauthorization of MRGO: 1) De-authorize MRGO as a Federal navigation channel and cease maintenance dredging. 2) Restoration of the Ridge at Bayou La Loutre 3) Channel severance or constriction at other locations (four or preferably more additional locations). The constrictions must be planted with dense native wetlands vegetation to root them in place. 4) Restoration/Maintenance of the narrow land between Lake Borgne and the MRGO. 5) Restoration/Rehabilitation of bank lines along the MRGO. Place dredged material to a height of 3-5 feet to reclaim as much of the original 1965 bank lines as reasonable, especially on the south bank. Plant native coastal vegetation on the reclaimed banks and lateral fills. 6) Allow natural infill of the channel (especially the Sound Reach). 7) Expand riverine influence (Reintroduction of freshwater from Mississippi River) USACE comments on the above measures: 1) This is part of the Recommended Plan. 2) This is being considered under LACPR. 3) The USACE proposes that only one structure on the MRGO near Bayou La Loutre is needed (see discussion of evaluation and elimination of Interim Report Alternative 2b in Sections 2.2 and 2.4 of this report). 4) Stabilization on some of the shore of Lake Borgne and marsh creation on the land bridge between the MRGO and Lake Borgne is proposed as part of operation and maintenance activities authorized under Public Law ) This is infeasible from an engineering viewpoint because it would involve 45-foot or longer sheet piles to keep the fill out of the reduced channel. It is also prohibitively expensive. 6) This would happen under the Recommended Plan 7) This is being considered under LACPR. The report also suggests additional actions to facilitate coastal conservation and restoration, and to improve storm and flood protection as follows: 1) Levee Improvement (Existing levees along the MRGO must be improved to withstand storm surge from a 500 year flood and be constructed such that overtopping does not result in levee collapse and failure) 2) Restore Historic Habitats in the Region (as in the LPBF s Comprehensive Management Plan 104

138 3) Facilitate the usage of treated effluent from wastewater plants. 4) Restore Marsh Landbridges of the Biloxi Marsh. 5) Restore Barrier Islands. USACE Comments on the above measures: All of these are being considered under LACPR. 4.7 LETTER FROM NATIONAL AND LOCAL ENVIRONMENTAL GROUPS, DATED JANUARY 26, 2006 This letter was signed by representatives of Environmental Defense, National Audubon Society, National Wildlife Federation, Louisiana Wildlife Federation, American Rivers, Coalition to Restore Coastal Louisiana, Gulf Restoration Network, the Lake Pontchartrain Basin Foundation and Levees.org. The letter pointed out the following items that were included in the Preliminary Comprehensive Plan for De-authorizing the MRGO report and they called them Items of Agreement : 1) Closure of the MRGO channel to both shallow and deep-draft navigation by an armored earthen structure just south of Bayou La Loutre near Hopedale, Louisiana ; 2) Freshwater diversion into the MRGO and surrounding marshes (possibly in the vicinity of the Violet Canal); 3) Shoreline protection to prevent wetlands erosion (including maintenance of existing projects); 4) Habitat creation through the placement of sediment for rebuilding marshes, barrier islands, and ridges; 5) Increasing existing levee heights to new hurricane protection levels; 6) New hurricane protection levee alignments or surge protection structures. USACE Comments on the above measures: 1) This is the Recommended Plan. 2) This is being considered under LACPR. 3) Shoreline protection on the MRGO and Lake Borgne are proposed as part of operation and maintenance activities authorized under Public Law Maintenance of existing rock is being considered under LACPR. 4) This is being considered under LACPR. 5) This is being considered under LACPR. 6) This is being considered under LACPR. The letter also stated that the following items are also essential for protecting New Orleans and St. Bernard Parish from future storms and should be included in the final plan for the MRGO: 1) The levees in St. Bernard Parish need to be not only higher, but better protected. Significant protection can be gained by rebuilding the banks of the MRGO, beginning with the banks in front of the St. Bernard levee, and planting new land 105

139 with dense native vegetation. Levees should also be armored with hard structure and be designed to be overtopped. 2) The closure of the MRGO by itself would not restore the fresh wetland (swamp) habitats destroyed by the MRGO, which would buffer storm surge. In addition to the proposed diversion at Violet, the plan should include the significant opportunity to beneficially use treated wastewater from the New Orleans Sewage plant to rebuild wetlands near the MRGO. 3) The plan calls for only one closure at Bayou La Loutre which would primarily address saltwater intrusion. Additional constrictions or closures are needed along the channel to reduce the induced effects on surge by the channel and to break wave fetch and reduce water velocity. USACE Comments on the above measures: 1) This is infeasible from an engineering viewpoint because it would involve 45-foot or longer sheet piles to keep the fill out of the reduced channel. It is also prohibitively expensive. Work on the levees is being considered under LACPR. 2) This is being considered under LACPR. 3) The USACE proposes that only one structure on the MRGO near Bayou La Loutre is needed (see discussion of evaluation and elimination of Interim Report Alternative 2b in Sections 2.2 and 2.4 of this report). The letter concludes with the following statement: With congressional appropriation, the first phase of closure must be completed in 2008 and include at least a closure at Bayou La Loutre and rebuilding of the MRGO s south bank in front of the St. Bernard levee. USACE response: The USACE is moving as fast as possible to complete a plan to de-authorize the MRGO channel from the GIWW to the Gulf of Mexico to both deep- and shallow-draft navigation and to place a total closure structure near Bayou La Loutre. As described above, partially filling the MRGO in front of the St. Bernard levee is infeasible. 4.8 MRGO WEB PAGE Additional measures to incorporate public input include an internet web page. The web page ( offers interactive capability allowing visitors to submit information and opinions via . The page also includes a digital library of publications related to the history of the channel, maps depicting the area, a calendar of events, minutes of stakeholder meetings, a transcript of the October 28, 2006 public meeting, the Interim Report to Congress and the Draft Final Report to Congress/Draft LEIS. In addition, notes from the May 19, 2007 public information meeting, along with the presentation slides, have been added. The information is intended to serve as a resource for the study team and interested stakeholders. 4.9 PUBLIC MEETINGS A public meeting was held on October 28, 2006 at the University of New Orleans and involved an open house where stakeholder groups were offered display space to present their points of view. More than 150 people attended the public meeting, which included 106

140 a formal presentation of the study process and scope from the USACE and an open comment period for public statements from citizens, organizations, and elected officials. Public comments made in this meeting were influential in plan formulation for the Interim Report to Congress. A public information meeting was held on May 19, 2007 at Nunez Community College in Chalmette, Louisiana. The meeting offered attendees an opportunity to view a series of posters presented by the USACE on the study. In addition, various stakeholders displayed information and interacted with the meeting attendees. More than 100 attendees listened to a formal presentation regarding the alternatives evaluated in detail and the Recommended Plan. Following the presentation, attendees had the opportunity to ask questions. All attendees were made aware of the study schedule and process AREAS OF CONCERN AND CONTROVERSY Construction of the MRGO Project resulted in the conversion of marsh, wetland forest and shallow open water habitat (USACE 1999). Erosion causes additional acres to be lost each year along the MRGO channel (USACE 2004). Citizens are concerned about coastal erosion, populations of wildlife and fisheries, and increased salinity in area water bodies. Many members of the public also feel that the loss of wetlands exacerbated the flooding of St. Bernard Parish during Hurricane Katrina. Many citizens of Orleans and St. Bernard Parishes firmly believe that the Inland Reach of the MRGO serves as a storm surge pathway during hurricanes. A number of reports concluded that the Inland Reach of the MRGO contributes very little to flooding when the surrounding marshes are inundated. Reports also indicate that to prevent storm sure in Lake Borgne from reaching the IHNC or GIWW Reach of the MRGO, flow through the GIWW Reach of the channel must be dramatically reduced or eliminated. The USACE is actively planning, designing and building numerous upgrades and new system components to increase the level of hurricane protection for the entire area. The connectivity between Lake Borgne and the GIWW Reach of the MRGO and IHNC is being addressed through efforts to provide comprehensive hurricane and storm protection through the Lake Pontchartrain and Vicinity Hurricane Protection project 100-year protection effort. See Section 1.8 and Appendix D for further discussions on the MRGO and storm surge. Stakeholders in the navigation industry have expressed concerns that when the MRGO is de-authorized from the GIWW to the Gulf of Mexico, shallow-draft vessels would no longer be able to use the channel as an alternate route when the Inner Harbor Navigation Canal Lock is congested or inoperable. Industry members believe this could present a serious problem for fuel transport and movement of other vital commodities. In evaluating this concern the USACE determined that this potential event would be very rare. Based upon the economics evaluation of this study, expenditures to construct and maintain a shallow-draft feature for MRGO traffic is not justified. As such, the USACE, navigation industry representatives, and leaders from St. Bernard Parish are willing to work together to identify suitable alternative routes to alleviate this potential issue. 107

141 The following options have been identified as potential alternative routes around the IHNC-GIWW-MRGO system (see Figure 4.1): 1. Mississippi River to Baptiste Collette Bayou and into Breton Sound and Chandeleur Sound and up to Mississippi Sound to rejoin the GIWW. A drawback of this option is the potential lack of adequate draft in the reach between the mouth of Baptiste Collette Bayou and Mississippi Sound. In addition, navigation safety concerns could be a factor because of the long expanse of open water that would be traversed on this route. 2. Mississippi River north to the Ohio and Tennessee Rivers to eventually join the Tennessee-Tombigbee Waterway and south into Mobile Bay to rejoin the GIWW. A drawback of this option is the much greater time and distance required. 3. Mississippi River to Baptiste Collette Bayou and into Breton Sound and north up to the back retainer canal on the south side of the MRGO spoil area and up to Bayou La Loutre at Hopedale to enter the MRGO and travel up to rejoin the GIWW in the vicinity of Michoud. A drawback of this option is the potential lack of adequate draft in the reach between the mouth of Baptiste Collette Bayou and the back retainer canal and the segment up the retainer canal to Hopedale. 4. Mississippi River to Baptiste Collette Bayou and into Breton Sound and north up to the mouth of Bayou La Loutre in Bay Eloi and then through Bayou La Loutre to enter the MRGO and travel up to rejoin the GIWW in the vicinity of Michoud. A drawback of this option is the potential lack of adequate draft in the reach between the mouth of Baptiste Collette Bayou and Bayou La Loutre. 5. Emergency removal of a portion of the rock total closure structure in the event of prolonged delays or inoperability of the IHNC Lock if authorization and funding are available. A cost estimate for this option has been developed and included in Appendix C. A drawback of this option is the potential lack of adequate draft in the reach between the mouth of Baptiste Collette Bayou and the Sound Reach of the MRGO. Additional work would be needed to define implementation criteria and to identify responsible parties because under the Recommended Plan the Federal government would no longer own or maintain any MRGO features from the GIWW to the Gulf of Mexico. The USACE will continue to develop these and other options in coordination with stakeholder groups. One possibility would be to consider efforts to improve the condition of the IHNC Lock through maintenance actions, which may improve the efficiency and reliability of the IHNC Lock and reduce the desire for an alternative route. Stakeholders in the shallow draft navigation industry have expressed concern that prolonged closure of the Inner Harbor Navigation Canal (IHNC) Lock with no alternate route available will cause significant income and employment impacts to businesses that rely on shipments traversing the IHNC Lock and that these impacts were ignored in 108

142 economic evaluations. However, as specified in USACE guidelines, the effects on income levels and employment levels generally fall into the Regional Economic Development (RED) account. These effects are considered to be RED in nature because, 1) increases or decreases in income/employment levels in one region will tend to be offset by increases or decreases in income/employment levels in another region resulting in a minimal net effect to the nation, and, 2) losses in one region that are not captured by another region can often be made up at a later date in the initially impacted region. This is not to say that the income/employment impacts can not be National Economic Development (NED) in nature, or that the impacts are insignificant at a regional level, but that from a national perspective the net impacts are likely to be small. Given that this is the case and that NED impacts take priority over RED impacts, the economic evaluation performed for the MRGO De-Authorization Study chose not to quantify income/employment implications. Some groups are concerned that the replacement of the IHNC Lock is somehow directly connected to the de-authorization of MRGO to deep-draft navigation. Although these projects are related, the Recommended Plan is in no way dependent on the replacement of the lock or vice versa. Some vessels may choose to utilize Bayou La Loutre, a Federally authorized channel, to access Chandeleur Sound and numerous waterways in the Biloxi Marshes following installation of a total closure structure on the MRGO channel. Bayou La Loutre has a controlling depth of six feet limiting vessels to recreational and commercial fishing boats, small tugs and barges, and oil field service boats. Although, the potential number of vessels that would use Bayou La Loutre and the potential impacts of diverted vessel traffic along the waterway cannot be quantified at this time, the overall environmental benefits of the Recommended Plan will far outweigh any potential impacts to Bayou La Loutre. Vessel traffic and shoreline erosion rates are monitored along Bayou La Loutre and other Louisiana waterways under private, state, and Federal efforts to implement coastal restoration plans RESOLUTION OF COMMENTS ON DRAFT LEIS All comments received during the 45-day public comment period on the draft LEIS are documented and responded to in Appendix P. All commenters will be sent a Notice of Availability of this Integrated Final Report to Congress and LEIS. 109

143 Figure 4.1 Alternative Routes Around the IHNC-GIWW-MRGO System 110